Find the mean absolute deviation for the set below. S = 65, 90, 85, 70, 70, 95, 55
A. 12.24
B. 75.7
C. 114
D. 32.67
(I’ll give points + brainalist)

Answers

Answer 1

Answer:

A) 12.24

Step-by-step explanation:

Mean absolute deviation: 65, 90, 85, 70, 70, 95, 55 = 12.244897959184

Answer 2

Answer:

75.7

Step-by-step explanation:


Related Questions

6,328 divide by 56 does anyone know

Answers

Answer:

113

Step-by-step explanation:

determine the fifth percentile of the standard normal distribution as a decimal rounded to the nearest hundredth.

Answers

The fifth percentile of the standard normal distribution is -1.64.

In the given question, we have to determine the fifth percentile of the standard normal distribution as a decimal rounded to the nearest hundredth.

The standard normal distribution, commonly known as the z-distribution, is a unique type of normal distribution in which the mean and standard deviation are both equal to 1. Any normal distribution's values can be transformed into z scores to normalise it. Z score shows the amount of standard deviations from the mean that each consists of numbers.

Since, X is normally distributed.

P(X< c) = 0.05

Using Z table

c = -1.645

Fifth percentile = -1.64

To learn more about the standard normal distribution link is here

brainly.com/question/29509087

#SPJ4

The best approximation, in cubic inches, to the increase in volume of a sphere when the radius is increased from 3 to 3.1 inches, is Use V = Tr3 (a) 0.04n/3 (b) 3.61 n'
(c) 0.04 n'
(d) 1.2 n'
(e)36 n'

Answers

The change in volume of the sphere or best approximation to the increase in the volume of the sphere is 3.6π cubic inches.

How is volume of a sphere calculated?

In simple words, when a sphere is placed in the space or three-dimension space, then the total space acquired by the sphere generally shows the volume of the sphere. The mathematical formula needed to determine the volume of a sphere is shown below,

[tex]V = \frac{4}{3} \pi r^3[/tex]

Calculation:

Given- The initial radius of the sphere is r1 = 3 inch and the final radius of the sphere is r2 = 3.1 inch.

Now , the change in the radius of the sphere is [tex]dR =[/tex][tex]r2 - r1 =\\[/tex] 3.1 - 3 = 0.1 inch.

The mathematical expression of the volume of a sphere is shown below,

[tex]V = \frac{4}{3}\pi r^3[/tex]   (here, [tex]r[/tex] is the radius of sphere)

Differentiate the above shown expression with respect to radius ([tex]r[/tex]) as shown below,

[tex]\frac{d}{dr} (V) = \frac{d}{dr} (\frac{4}{3} ) \pi r^3[/tex]

dV/dR = 4/3 π × d/dR(r^3)

          = 4/3 π × 3r^2

dV/dR = 4π r^2

∴ dV = 4π r^2 dR            ................(1)

Substitute all values in equation (1) and calculate the approximation as shown below,

dV =  4π r^2 dR

     =  4π (3)^2 × (0.1)

∴ dV = 3.6π cubic inches.

The change in volume of the sphere or best approximation to the increase in the volume of the sphere is 3.6π cubic inches.

To know more about volume of sphere, check out:

https://brainly.com/question/22807400

#SPJ4

How do I answer this assignment?
I do not understand

Answers

Answer:

number of caps is the ratio

blue + white + green = 96

5x + 4x + 7x = 96

16x = 96

x = 6

Blue caps : 5x = 5(6) = 30

white caps : 4x = 4(6) = 24

green caps : 7x = 7(6) = 42

total of : 96 caps

Therefore, a caps in the picture represent 6 caps

Step-by-step explanation:

heart and star pls <3 brainliest will be appreciated <3(っ◔◡◔)っ  -{ elyna s }-

Can I get help with this quick check

Answers

The common difference of the sequence is 70, the slope of the 1st and 2nd lines is 70, the slope of the 3rd and 4th points is 70, and the slope is constant.

What is the slope?

A line's slope is determined by how its y coordinate changes in relation to how its x coordinate changes. Y and x are the net changes in the y and x coordinates, respectively.

Given:

Time in minutes and jumping jack table, coordinates of lines (1, 70) and (2, 140)

(a)

Consider 70, 140, 210, and 280 as an arithmetic sequence then the common difference will be,

Common difference = 140 - 70 = 70

(b)

Calculate the slope of the line as shown below,

[tex]m = (y_2-y_1) / (x_2 - x_1)[/tex]

m = (140 - 70) / (2 - 1)

m = 70 / 1

m = 70

(c)

Calculate the slope for 3rd and 4th points,

m = (280 - 210) / (4 - 3)

m = 70 / 1

m = 70

(d)

As you can, the slope is constant, and the common difference is also constant.

To know more about the slope:

https://brainly.com/question/2491620

#SPJ1

Between which values does lie?

Answers

Answer:

lies between 10 and 11.

Step-by-step explanation:

We are asked to find the values between which  lies.

We know that square root of 100 is 10 and square root of 121 is 11.

Since  is between  and , therefore,  lies between 10 and 11.

Sam invests 1700 in a savings account that pays a nominal annual interest rate of 2.74% Sam makes no further payments or withdrawals from this account

David also invests 1700$ in a savings account that pays an annual rate of r% compounded yearly David makes no further payments or withdrawals from this account fund the value of r so that the amount in David’s account after 10 years will be equal to sams account

Answers

a.) The amount that Sammy will have in his account after 10 years will be= $2,165.8

$2,165.8b.) The value of 'r' required would be = 0.27%

What is interest rate?

Interest rate is defined as the rate at which an individual receives an amount of money from an investment made over a period of time.

The amount invested by Sam(P) = $1700

The interest rate(R) = 2.74%

The time of investment (T) = 10 years

Simple interest = P×T×R/100

= 1700×10×2.74/100

= 46580/100

= $465.80

Therefore, the amount that Sammy will have in his account after 10 years will be = $1700 + $465.80

= $2,165.8.

For David's account interest rate the following is carried out:

The amount invested by Sam(P) = $1700

The interest rate(R) = r%

The time of investment (T) = 10 years

Simple interest (SI) = $465.80

Using the formula for simple interest;

SI = P×T×R/100

Make R the subject of formula;

R = SI×100/P×T

R = 465.80×100/1700×100

R= 46580/170000

R= 0.27%

Learn more about simple interest here:

https://brainly.com/question/25793394

#SPJ1

Complete question:

Sam invests $1700 in a saving account that pays a nominal annual rate of interest of 2.74% compounded half-yearly. Sam makes no further payments to, or withdrawals from, this account. (a) Find the amount that Sam will have in his account after 10 years.

David also invests $1700 in a savings account that plays an annual rate of interest of r%, compounded yearly. David makes no further payments or withdrawals from this account. (b) Find the value of 'r' required so that the amount in David's account after 10 years will be equal to the amount in Sam's account.

Solve the equation -128 = 4x for x

Answers

Answer: -32

Step-by-step explanation:

To solve the equation -128 = 4x for x, we need to isolate the x variable on one side of the equation. We can do this by dividing both sides of the equation by 4. This gives us:

-128/4 = 4x/4

Dividing -128 by 4 gives us -32, so we have:

-32 = 4x/4

We can simplify this by dividing both sides by 4/4 to get:

-32 = x

Thus, the solution to the equation -128 = 4x is x = -32.

Can somebody please tell me how do i solves these. Thank you.

Answers

2. It is false that the differential equation is non-linear.

The statement regarding the differential equation y''y + (y')² = sin(x) is false.

3. Statement 3: fourth order and nonlinear differential equation.

How to classify the differential equations?

For a linear differential equation, the coefficients of y or the derivatives of y are either:

Constant terms.Other variables that are not y.

Hence the differential equation for question 2 is linear, as the coefficients of the derivatives are x and -1, neither of which is y, hence the statement is false.

For the differential equation y''y + (y')² = sin(x), we have that:

It is non-linear, as y multiplies y''.It is of the second order, as the order of the highest derivative is of 2.

For the differential equation in item 3, we have that:

It is of the fourth order, as the derivative of the third order multiplies the derivative of the first order.It is non linear, as the variable y multiplies the derivative of the third order of y.

Hence statement 3 is correct.

More can be learned about differential equations at https://brainly.com/question/18760518

#SPJ1

Find the y-intercept and the slope of the line.

y=-1/2-1/4x

y-intercept: ?

slope: ?

Answers

Answer: slope = -1/4 y-intercept = -1/2

Step-by-step explanation:

Given an equation in the form y = mx + b, m = slope and b = y-intercept.

We can rearrange y= -1/2 - 1/4x into that form.

y = -1/4x - 1/2

We can now obviously see that -1/4x is the slope, and -1/2 is the y-intercept.

What is the y-intercept

Answers

The point where the curve intercepts y axis
The y-intercept is the point where a function intercepts the y-axis. It can be found by inputting x=0 into a function and simplify to find f(x), which is the y-intercept. When x=0, there is no lateral change, so you are only focusing on the y-axis, meaning the y-intercept will lie on that x-coordinate. Essentially, there is no movement on the x-axis so that you can simply focus on the y-axis and it’s point of interception.

Perform the following mathematical operation, and report the answer to the appropriate number of significant figures.

1204.2 + 4.72613 = [?]

The answer is not 1208.92613​

Answers

Answer

Step-by-step explanation:

two tangents $\overline{pa}$ and $\overline{pb}$ are drawn to a circle, where $p$ lies outside the circle, and $a$ and $b$ lie on the circle. the length of $\overline{pa}$ is $12,$ and the circle has a radius of $9.$ find the length $ab.$

Answers

The value of tangent AB as calculated from the given data is 14.4.

The tangents to the circle as given are PA and PB.

Let the point of intersection of PO and AB be X.

PA = 12  

OA = 9

As given that the triangle is right angled we can use hypotenuse theorem to calculate PO,

PO = √ PA²  + OA²

= √ 144 + 81

= 15

Now , the given triangles are similar because,

 AX / AO  =  PA / PO

 AX / 9  =  12 / 15

Therefore, the value of X is,

X  =  7.2

Now we know that AB's midpoint is X,

Hence , AB = 2X = 14.4

Tangent is known as a point which passes through a circle only at one single point A circle can have infinite tangents.

To learn more about tangents

brainly.com/question/19064965

#SPJ4

What is the product of the 4 x and the 3 x cubed y squared minus 2 x y cubed?

Answers

Answer:

4xy ×3xy -2xy

12xy-2xy

10xy

An airline that wants to assess customer satisfaction chooses a random sample of 10 of its flights during a single month and asks all of the passengers on those flights to fill out a survey. This is an example of a
A) Multistage sample.
B) Stratified sample.
C) Cluster sample.
D) Simple random sample.
E) Convenience sample

Answers

An airline that wishes to measure customer satisfaction chooses ten of its flights at random over the course of a single month and requests that each passenger fill out a survey. A Cluster sample looks like this.

Why do we utilize cluster sampling?Cluster sampling should be used to study large, dispersed populations because interviewing every person would be costly, time-consuming, and occasionally impossible.Smaller, more comparable groups that represent the population under study can be produced via cluster sampling.You divide a population into groups, such as districts or schools, and then randomly select a sample from among these groupings when using the probability sampling approach known as cluster sampling. Each cluster should ideally be a miniature representation of the total population.An airline that wants to gauge customer happiness selects a haphazard sample of 10 of its flights over the course of a single month and asks each passenger to complete a survey. An illustration of a Cluster sample is this.

To learn more about Cluster sample refer to:

brainly.com/question/9910540

#SPJ4

Solve.(Refer to the picture)

Answers

Answer:

[tex]y=2.182[/tex]

Step-by-step explanation:

Solve for y.

[tex]3.082=y+\frac{9}{10}[/tex]

Move all terms not containing [tex]y[/tex] to the right side of the equation.

[tex]y=3.082-\frac{9}{10}[/tex]

Write [tex]\frac{9}{10}[/tex] as a decimal.

[tex]y=3.082-0.9[/tex]

[tex]y=2.182[/tex]

Howard Cunningham has a $90,000.00 whole life policy. What will the cash value of her policy be at the following anniversary dates?
(Include decimal places for cents in each answer, even when cents are not calculated. Use a thousands comma where applicable.)

Answers

Answer:

5 years = 2,700.00

25 years = 30,600.00

Step-by-step explanation:

Hey, these are difficult, I know.

I'll explain how you solve them.

In this case, $90,000.00 needs to first be divided by 1,000.

That gives us 90.

You then multiply 90 by 30, which is the 5 yr cash value.

That gives you 2,700.00.

Since you have 90, you next need to multiply that by 340 (25 yr cash value), which gives you 30,600.00.

Hope this helps.  Feel free to mark Brainliest.

Realiza las siguientes potencias

Answers

Answer:

-5/8

Step-by-step explanation:

5.(-2^-3)

-5. 1/2³

-5. 1/8

-5/8

What is the greatest common factor of 20 and 40?

Answers

What is the greatest common factor of 20 and 40?

20

Q. An arithmetic series has first term a and common difference d, where d is a prime number. The sum of the first n terms of the series is S, and Sm=39 S2m = 320 Find the value of d and the value of m Show clear algebraic working. (Total for question = 5 marks)​

Answers

Finding the values of d and the value of m with the algebraic working will give us the the value of d to be 7 and the value of m to be 3.

How do we calculate the values using the algebraic expression?

Finding the value of d, we know that the sum of the first n terms of an arithmetic series is given by:

S = n/2 * (2a + (n-1)d)

Since the sum of the first n terms is S and the sum of the first 2m terms is S2m, we can set up the following equation:

S = m/2 * (2a + (m-1)d)

S2m = 2m/2 * (2a + (2m-1)d)

Substituting the given values for S and S2m into these equations, we get:

39 = m/2 * (2a + (m-1)d)

320 = 2m/2 * (2a + (2m-1)d)

Solving for d in each equation, we find that d = -7 in the first equation and d = 7 in the second equation. Since d must be a prime number, the only possible value for d is 7.

Now that we know the value of d, we can solve for m. Substituting the value of d back into one of the equations and solving for m, we get:

39 = m/2 * (2a + (m-1)7)

78 = m * (2a + (m-1)7)

78 = m * 2a + 7m^2 - 7m

7m^2 - m - 78 = 0

We can solve for m using the quadratic formula:

m = (-1 +/- sqrt(1^2 - 4*7*(-78)))/(2*7)

= (-1 +/- sqrt(2521))/14

= (-1 + 49)/14 = 3

= (-1 - 49)/14 = -7

Since m must be a positive integer, the only possible value for m is 3.

Therefore, the value of d is 7 and the value of m is 3.

learn more about algebraic expression: https://brainly.com/question/4344214

#SPJ1

Write the following expression without negative exponents and without parentheses. (7x)^{-2} (7x) −2

Answers

[tex]\frac{1}{(7x)^2}[/tex] is the expression without negative exponents.

What are exponents and indices?

Exponent is defined as the method of expressing large numbers in terms of powers. That means, exponent refers to how many times a number multiplied by itself.

An index, or power, is the small floating number that appears after a number or letter. The plural of index is indices.

According to the given question:

(7x)^{-2} is the given indices expression

To expression without negative exponent, the expression

can be written as

[tex](7x)^{-2} = \frac{1}{(7x)^2}[/tex]

Since the exponent -2 is on the whole 7x term. So, the whole term moves to denominator to make the exponent positive.

Therefore [tex]\frac{1}{(7x)^2}[/tex] is the expression without negative exponents

To know more about exponent and indices visit

https://brainly.com/question/17385915

#SPJ1

find the area of shaded region

Answers

The answer is area d beacause as you can see there is a small shaded square inside and there is a line that is dividing it in half so it’s in d

A rectangular park is 4a m and 3a m broad, find it's area in m2​

Answers

Answer:

Area = 12a m²

Step-by-step explanation:

Given information,

→ Length = 4a m

→ Width = 3a m

Now we have to,

→ find the area of rectangular park.

Formula we use,

→ Area = L × W

Then the area of rectangle is,

→ L × W

→ 4a × 3a

→ (4 × 3)a

→ 12a m²

Therefore, the area is 12a m².

Kadeesha bought snacks for her team's practice. She bought a bag of popcorn for $ 1.59 and a 5-pack of juice bottles. The total cost before tax was $13.34. Which equation or tape diagram could be used to represent the context if j represents each bottle of juice costs?
A
5 j=1.59-13.34
C
1.59 j=13.34-5

Answers

The equation or tape diagram could be used to represent the context if j represents each bottle of juice costs is; Option D tape diagram

How to Represent Algebraic equations?

We are told that;

1 bag of popcorn costs $1.59

She bought a 5-pack of juice bottles

Total cost before tax = $13.34

Now, we are told that j represents each bottle of juice costs. Thus;

Cost of the 5 packs of juice = 5j

Thus, the equation of the total cost before tax is;

1.59 + 5j = 13.34

Looking at the options, only the tape diagram in option D correctly represents the required equation.

Read more about Algebraic equations at; https://brainly.com/question/4344214

#SPJ1

small regional carrier accepted 22 reservations for a particular flight with 18 seats. 16 reservations went to regular customers who will arrive for the flight. Each of the remaining passengers will arrive for the flight with a 58% chance, independently of each other.
(Report answers accurate to 4 decimal places.)
Find the probability that overbooking occurs. Find the probability that the flight has empty seats.

Answers

The probability that overbooking occurs is 0.7920 and the probability that the flight has empty seats is 0.0510 respectively.

How to calculate probability?

We remove the 16 regular customers and their seats from consideration. Thus, we consider the 22 - 16 remaining customers = 6 and the 18-16 = 2 seats overbooking means 3 or more of the 6 remaining passengers; each has a 58% chance remaining.  We can either use the binomial distribution formula P(x) = C(6, x) .58^x .42^(6-x) or use packages that provide the result, including cumulative probabilities.

Calculation:

Overbooking = 1 - P(X <= 2)   In Excel, we use =1 - binom.dist(2,6,.58,1)   ; the 1 is for cumulative.

The solution is 0.7920

Probability of empty seats = P(x <= 1)  = binom.dist(1,6,.58,1) = 0.0510

The probability that overbooking occurs is 0.7920 and the probability that the flight has empty seats is 0.0510 respectively.

To know more about Probability check out:

https://brainly.com/question/24756209

#SPJ4

In the arrangement of letters and numerals below, by how many different paths can one spell AMC8? Beginning at the A in the middle, a path allows only moves from one letter to an adjacent (above, below, left, or right, but not diagonal) letter. One example of such a path is traced in the picture.8 C 88 C M C 8C M A M C8 C M C 88 C 8(A) 8(B) 9(C) 12(D) 24(E) 36

Answers

In the arrangement of letters and numericals, the total number of different paths can one spell AMC8 are 24 in count.

What is counting principle?

A basic counting principle is that if there are p ways to do one thing and q ways to do another, then there are p × q ways to do both. Possible results of experiments. The counting principle can be extended to situations where there are two or more alternatives.

We have, the arrangement of letters and numericals in above figure such that

Beginning at the A in middle M a path allows only moves from one letter to an adjacent either above, below, left, or right, but not diagonal letter.

There are three different kinds of paths that are on the above diagram to get the required pattern. The first kind is when you directly count A, M, C in a straight line. The second is when you count A, turn left or right to get M, then go up or down to count 8 and C. The third is the one where you start with A, move up or down to count M, turn left or right to count C, then move straight again to get 8.

There are 8 paths for each kind of path, making for 8×3= 24 paths.

Hence, the required paths are 24 in count.

To learn more about Counting principle, refer:

https://brainly.com/question/29774420

#SPJ4

on Monday Therease went to the doctor and got an antibiotic for strep throat. The doctor told her take a dose of 4.8 ml every 12 hours for 7 days. If Thereas took her first dose at 9:00 AM on Monday, what day and time should she take her 7th dose?

Answers

Therease should take her 7th dose on Friday at 9:00AM

What is time ?

Time can be described in mathematics as an ongoing and continuous series of events that take place one after another, from the past through the present, and into the future. The duration of events or the gaps between them can be measured, compared, or even ordered using time.

Time is the ongoing progression of existence and things that happen in what seems to be an irrevocable order from the past, present, and forward into the future.

Time is defined by physicists as the flow of events from the past through the present and into the future. In essence, a system is timeless if it is unchanging. When describing events that take place in three-dimensional space, time can be thought of as the fourth dimension of reality.

The doctor told her to take a dose of 4.8 ml every 12 hours for 7 days.

If Theresa took her first dose at 9:00 AM on Monday,

Simply add 12 hours every time up to the 7th dose,

First dose  ----> 9:00 AM on Monday,

Second dose  ----> 9:00 PM on Monday,

Third dose  ----> 9:00 AM on Tuesday,

Fourth dose  ----> 9:00 PM on Tuesday,

Fifth dose  ----> 9:00 AM on Thursday,

Sixth dose  ----> 9:00 PM on Thursday,

Seventh dose  ----> 9:00 AM on Friday,

Hence, Theresa should take her 7th dose at 9:00 AM on Friday.

To learn more about time from the given link  

https://brainly.com/question/2854969

#SPJ1

Hummingbird feeders are filled with hummingbird nectar. Hummingbird
nectar is made using a ratio of 1 part sugar to 3 parts water.
How much sugar, in ounces, is needed to make 28 ounces of
hummingbird nectar? Show your work in the provided space.

Answers

The amount of sugar, in ounces, that is needed to make 28 ounces of hummingbird nectar is 7 ounces.

How to find the ounces of sugar needed ?

Hummingbird nectar is said to be made by using a ratio of 1 part sugar to 3 parts water. For every 1 ounce of sugar therefore, there would be 3 ounces of water.

Put together, this would give 4 ounces. And the percentage of sugar in this 4 ounces would be:

= 1 / 4

= 25 %

If 28 ounces of hummingbird nectar needed to be made, the sugar needed is :

= Percentage of sugar x Ounces of hummingbird nectar

= 25 % x 28

= 7 ounces of sugar

Find out more ratio at https://brainly.com/question/29465645

#SPJ1

Kate Drew has been hand-painting wooden Christmas ornaments for several years. Recently, she has hired some friends to help her increase the volume of her business. In checking the quality of the work, she notices that some slight blemishes occasionally are apparent. A sample of 24 pieces of work resulted in the following number of blemishes on each piece: 1,1,2,3,1,0,2,0,0,1,3,1,0,1,2,0,0,2,1,2,3,2,1,1. Develop upper and lower control limits (99.73%) for the number of blemishes on each piece. Is the process in control? Why? **Please do this in excel*

Answers

A sample of 24 pieces of work is considered for the checking the quality of the work,

a) Upper control limit of 99.73% confidence interval is 4

Lower control limit of 99.73% confidence interval is Zero.

The process is in control because all the values of the blemishes per unit are lie within the control limits .

What is Control Limits?

The Control limits consist of two limits lower control limit and upper control limit within which the value of the statistical observations of a product are expected to lie. If the values lie outside these limits, then the process is called out of statistical control. We have,

Kate Drew has been hand-painting wooden Christmas ornaments for several years.

Sample size = 24 pieces

confidence level = 99.73% = 0.9973

The number of blemishes per unit is given as:

1,1,2,3,1,0,2,0,0,1,3,1,0,1,2,0,0,2,1,2,3,2,1,1.

The control limits are to be computed for the number of defects per piece . Let us consider the number of defects per piece be denoted by c. In that case, the control limits for c chart are used. The upper control limit (UCL) and lower control limit (LCL) for c chart is given by,

UCL = c-bar + 3 s.d

LCL = c-bar - 3 s.d

where c-bar = 1/n(€c) average number of defects

So, c-bar is computed as,

c-bar = (1+1+2+3+1+0+2+0+0+1+3+1+0+ 1+2+0 +0+2 + 1+2 +3+ 2+1+1) /24 = 30/24 = 1.25

put the data in Excel sheet and calculate required limits using Excel Commands.

Excel Command for Average, c-bar

=Average( Range of numbers who's average you want to calculate )

In my excel sheet, = Average ( H2 : H25)

= 1.25

Excel Command for Standard deviations,

=STDEV( numbers who's standard deviations you want to calculate)

here, =STD(H2:H25) , output= 0.98907

UCL = 1.25 + 3( 0.98907)

= 4.217

LCL = 1.25 - 3( 0.98907)

= - 1.717

but defective item can never be negative so, Lower control limit is Zero.

Hence, for the given data, the upper control limit for the number of defects is 4 and the lower control limit is 0.

To learn more about Contral limits of confidence interval, refer:

https://brainly.com/question/15712887

#SPJ4

Assume that the helium porosity (in percentage) of coal samples taken from any particular seam is normally distributed with true standard deviation 0.72.
(a) Compute a 95% CI for the true average porosity of a certain seam if the average porosity for 23 specimens from the seam was 4.85. (Round your answers to two decimal places.)
(b) Compute a 98% CI for true average porosity of another seam based on 14 specimens with a sample average porosity of 4.56. (Round your answers to two decimal places.)
(c) How large a sample size is necessary if the width of the 95% interval is to be 0.42? (Round your answer up to the nearest whole number.)
(d) What sample size is necessary to estimate true average porosity to within 0.24 with 99% confidence? (Round your answer up to the nearest whole number.)

Answers

For the normal distribution of helium porosity (in percentage) of coal samples,

a) 95% CI for the true average porosity of a certain seam is equals to ( 4.56 , 5.14 ).

b) A 98% CI for true average porosity of another seam based on 14 specimens is equals to (4.11 , 5.01).

c) Sample size with width of confidence interval 0.42 is 45.

d) Necessary Sample size to estimate true average porosity to within 0.24 is 60.

We have Assume that the helium porosity (in percentage) of coal samples taken from any particular seam is normally distributed.

Standard deviations, σ = 0.72

a)Average porosity of specimens , X-bar = 4.85

Sample size, n = 23

Confidence level , alpha = 95% = 0.95

From Normal Distribution table

Z for 95% Confidence Interval = 1.96

so,95% Confidence interval = (x-bar - Z× σ/sqrt(n) , x-bar + Z×σ/sqrt(n) )

plugging all known values in above formula,

= ( 4.85-1.96×0.72/sqrt(23) , 4.85+1.96×0.72/sqrt(23) )

So, 95% Confidence interval = ( 4.56 , 5.14 )

b)Now, Sample size, n = 14

sample mean, X-bar = 4.56

from normal distribution Z- table

Z-score for 98% CI is equal to 2.33

so,98% CI = (x-bar-Z×σ/sqrt(n) , x-bar+Z×σ/sqrt(n) )

= ( 4.56-2.33×0.72/√14 , 4.56+2.33×0.72/√14 )

98% CI = ( 4.11 , 5.01 )

c)Using the normal Distribution Z- table

Z for 95% CI = 1.96

Width of confidence interval = 0.42

we have to determine the sample size, n .

Using formula, Width = 2×Z×σ/sqrt(n)

=> n = (2×Z×sd/width)²

=> n= (2×1.96×0.72/0.42)²

=> n = 45.15

=> n = 45 ( whole number)

d) From normal distribution table

Z for 99% CI = 2.58

Margin of error, ME = 0.24

margin of error = ME = Z×σ/sqrt(n)

=> n = (Z× σ/ME)²

=> n= (2.58×0.72/0.24)²

=> n = 59.9

=> n = 60

Hence, required sample size is 60.

To learn more about Confidence interval, refer:

https://brainly.com/question/17212516

#SPJ4

Other Questions
What do you think is the most effective method quoting paraphrasing or summarizing of integrating sources into your writing and why? The basic complaint of protesting colonists can be summed up with which of the following phrases?"No justice, no peace""Give me liberty or give me death""No taxation without representation""Join or die" What causes solid to change to a liquid? To compile a program by which a 4-digit natural number is entered from the interval [1000.. 9999]. 2 new 2-digit numbers are formed from this number. The first number is formed from the 1st and 4th digits of the entered number. The second number is formed from the 2nd - 3rd digit of the entered number. Display whether the 1st new number is displayed on the screen e is less than Quadrilateral ABCD with vertices A(-4, 1), B(-2, 3), C(0, -2) and D(-5, -2): k=3 opponents of active stabilization policy a. advocate a monetary policy designed to offset changes in the unemployment rate. b. believe that the political process creates lags in the implementation of fiscal policy. c. argue that fiscal policy is unable to change aggregate demand or aggregate supply. d. feel that fiscal and monetary policy should only be used to counteract short-run fluctuations but not long-run goals. In what ratio is the line segment joining (- 1/3 and 4 7 divided at the point? what is frontal EEG asymmetry and evaluate its relationship with individual differences in either depression OR anxiety. Identify four results of the Louisiana Purchase.A.U.S. access to natural resources like lumber and animal fursB.The spread of slavery into the western territoriesC.U.S. expansion from the Atlantic to the Pacific OceanD.Spain losing control over all lands in North AmericaE.Conflicts with American Indians over land useF.U.S. control of the Mississippi River and the New Orleans seaport What substance are found in the plasma? [URGENT!] - Acids and Basesa) What is the pH of a solution in which 25.0 ml of a 0.400 M solution of HCl is added to 75.0 ml of a 0.500 M solution of ammonium hydroxide?b) If 0.050 moles of KOH were added to the buffer solution, what would be the resulting pH?c) Explain what chemical reaction(s) happen as KOH is added to the buffer solution. How do you prove closed under addition? When exposed to a chemical What should you do? When the Federal Open Market Committee (FOMC) directs that Treasury securities be sold in the open market, this will do which of the following? an element X forms an oxide with formula X2O3(a) state the valency of X (b) write the formula of This is finance literacy help me ASAP!!!! Which statement best describes a way the railroad contributed to the development of Georgia? Why did African slavery expand in the 17th century? How will your studies at the University of Helsinki contribute to the advancement of knowledge in your chosen field of study? Is the University of Helsinki your first choice? If so, please explain why. How would the scholarship improve your commitment and contribution to the degree programme? What is the first step to performing hardware maintenance? A Turn off the computer and remove its power source B. Install anti-virus software. C. Disconnect all the input and output devices D. Disconnect the UPS and surge suppressor Save Answer