The average breaking strength of a certain brand of steel cable is 2000 pounds, with a standard deviation of 100 pounds. A sample of 20 cables is selected and tested. Find the sample mean that will cut off the upper 95% of all samples of size 20 taken from the population. Assume the variable is normally distributed.

Answers

Answer 1

Answer:

The sample mean that will cut off the upper 95% of all samples of size 20 taken from the population is of 1963.2 pounds.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

The average breaking strength of a certain brand of steel cable is 2000 pounds, with a standard deviation of 100 pounds.

This means that [tex]\mu = 2000, \sigma = 100[/tex]

A sample of 20 cables is selected and tested.

This means that [tex]n = 20, s = \frac{100}{\sqrt{20}} = 22.361[/tex]

Find the sample mean that will cut off the upper 95% of all samples of size 20 taken from the population.

This is the 100 - 95 = 5th percentile, which is X when Z has a p-value of 0.05, so X when Z = -1.645. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]-1.645 = \frac{X - 2000}{22.361}[/tex]

[tex]X - 2000 = -1.645*22.361[/tex]

[tex]X = 1963.2[/tex]

The sample mean that will cut off the upper 95% of all samples of size 20 taken from the population is of 1963.2 pounds.


Related Questions

Slope=6and passes through (4,-1)

Answers

Answer:

Step-by-step explanation:

If you need the equation:

point slope form is:

y-y1 = m(x-x1)

m is the slope and (x1,y1) is a point on the line.

y- (-1) = 6(x-4)

If you want standard form:

y= 6x -24 -1

y=6x-25

Let sin A = -5/13 with 270 degrees < A < 360 degrees and cos B = -15/17 with 90 degrees < B < 180 degrees find sin (A+B)

Answers

Answer:

Step-by-step explanation:

Function: g(x) = 2x2 - 8


Answers

Answer:

f(x)= √ 1 2 x + 4 For x ≤ 0

Step-by-step explanation:

What is the constant of variation k of the direct variation y=KP through (-3, 2)

Answers

Answer:

isisis

Step-by-step explanation:

ISO’s

Answer:

-2/3

Answer: The constant of variation k for y = kx through (-3, 2) is k = -2/3.

find all the missing measurement​

Answers

Answer:

fshscssjjsv 57

Step-by-step explanation:

fsuevwuwhw 58

The California State University (CSU) system consists of 23 campuses, from San Diego State in the south to Humboldt State near the Oregon border. A CSU administrator wishes to make an inference about the average distance between the hometowns of students and their campuses. Describe and discuss several different sampling methods that might be employed. (Select all that apply.) There are no potential problems with self reporting of distances.

Answers

Answer:

1)The sample could be generated by taking a stratified random sample by taking a simple random sample from each of the 23 campuses and again asking each student in the sample to report the distance from their hometown to campus.

2)One could take a simple random sample of students from all students in the California State University system and ask each student in the sample to report the distance from their hometown to campus.

3)Certain problems arise with self reporting of distances, such as recording error or poor recall.

Step-by-step explanation:

1)The sample could be generated by taking a stratified random sample by taking a simple random sample from each of the 23 campuses and again asking each student in the sample to report the distance from their hometown to campus.

2)One could take a simple random sample of students from all students in the California State University system and ask each student in the sample to report the distance from their hometown to campus.

3)Certain problems arise with self reporting of distances, such as recording error or poor recall.

Please Help! What's the rule that represents the sequence 13, 27, 41, 55, ...?

Answers

the answer is B. an = 13 + 14(n-1)

Answer:

B

Step-by-step explanation:

an = a+(n-1)d

an=13+(n-1)14

d=14

Help please :) Whoever helps and gets answer correct gets Brainliest!

Answers

Answer:

1/8 is the slope

Step-by-step explanation:

Answer:

slope = 8

Step-by-step explanation:

Calculate the slope m using the slope formula

m = [tex]\frac{y_{1}-y_{1} }{x_{2}-x_{1} }[/tex]

with (x₁, y₁ ) = (1, 26) and (x₂, y₂ ) = (2, 34) ← 2 ordered pairs from the table

m = [tex]\frac{34-26}{2-1}[/tex] = [tex]\frac{8}{1}[/tex] = 8

what is proportion as applied in mathematics​

Answers

Answer:

como se siente el actor al presentar la obra hola

You have 8 quarts of milk. You need 1.25 cups to make one serving of deep fried chicken. How many servings can you make?

Answers

Answer: 25.6 servings (partial serving) / 25 servings (whole serving)

Step-by-step explanation:

Concepts:

As we can see from the question, there are two units applied. [Quarts] and [cups]; therefore, we need to do the unit conversion.

1 quart = 4 cups

Solve:

Step one: Convert quarts into cups

1 quart = 4 cups8 quarts = 4 × 8 = 32 cups

Step two: Divide the cups to find the number of servings

32 cups / 1.25 cups = 25.6 servings

**Disclaimer** I am not sure about the rules that you apply in mathematics. Here, the answer is not an integer. I am concerned whether you would allow partial servings. In my understanding, the servings shall be a whole, thus should be rounded. However, if you are fine with decimals, then you have the choice.

Hope this helps!! :)

Please let me know if you have any questions

Each month, Terrance spends $128.00 on his car payment, $63.00 for car insurance, and $45.00 on gas. Round each amount to the nearest ten and estimate the amount of money Terrance spends each month to own a vehicle. $240.00 $220.00 $230.00 $210.00 which one is it

Answers

Answer:

$240

Step-by-step explanation:

Rounding each amount to the nearest 10

Car $128 = $130

Insurance $63 = $60

Gas $45 = $50

130 + 60+ 50 = $240

Need help with the answers that have been left Blank don’t understand how to do them

Answers

Step-by-step explanation:

d=20 J.

E=2,N,J

this is your answer

In a tram, 12% of the passengers go without a ticket. What can be the largest number of passangers in the tram, if its not greater than 60

45 POINTS

Answers

Answer:

Approximately 53 passengers

Step-by-step explanation:

12% of the passengers go without a ticket
so that means 88% of the passengers go with ticket

The largest number of passengers in the tram cannot be greater than 60

Solution:

Set up the dimensions this way:

•part/whole = part/whole

•88%/100% = ?/60
________________________

Then multiply 60 x 88

60 x 88 = 5280

Then divided 5280 by 100

5280 divided by 100 = 52.8

________________________

So the largest number of passengers in the tram is approximately 53

Use the limit comparison test to determine whether ∑n=19∞an=∑n=19∞8n3−2n2+196+3n4 converges or diverges.

(a) Choose a series ∑n=19∞bn with terms of the form bn=1np and apply the limit comparison test. Write your answer as a fully simplified fraction. For n≥19,

limn→∞anbn=limn→∞


(b) Evaluate the limit in the previous part. Enter ∞ as infinity and −∞ as -infinity. If the limit does not exist, enter DNE.
limn→∞anbn =


(c) By the limit comparison test, does the series converge, diverge, or is the test inconclusive?

Answers

Answer:

Diverges

General Formulas and Concepts:

Algebra I

Exponential Rule [Dividing]:                                                                         [tex]\displaystyle \frac{b^m}{b^n} = b^{m - n}[/tex]

Calculus

Limits

Limit Rule [Variable Direct Substitution]:                                                     [tex]\displaystyle \lim_{x \to c} x = c[/tex]

Series Convergence Tests

P-Series:                                                                                                         [tex]\displaystyle \sum^{\infty}_{n = 1} \frac{1}{n^p}[/tex]Direct Comparison Test (DCT)Limit Comparison Test (LCT):                                                                       [tex]\displaystyle \lim_{n \to \infty} \frac{a_n}{b_n}[/tex]

Step-by-step explanation:

Step 1: Define

Identify

[tex]\displaystyle \sum^{\infty}_{n = 19} \frac{8n^3 - 2n^2 + 19}{6 + 3n^4}[/tex]

Step 2: Apply DCT

Define Comparison:                                                                                     [tex]\displaystyle \displaystyle \sum^{\infty}_{n = 19} \frac{n^3}{n^4}[/tex][Comparison Sum] Simplify:                                                                         [tex]\displaystyle \displaystyle \sum^{\infty}_{n = 19} \frac{1}{n}[/tex][Comparison Sum] Determine convergence:                                             [tex]\displaystyle \displaystyle \sum^{\infty}_{n = 19} \frac{1}{n} = \infty , \ \text{div by P-Series}[/tex]Set up inequality comparison:                                                                     [tex]\displaystyle\frac{8n^3 - 2n^2 + 19}{6 + 3n^4} \geq \frac{1}{n}[/tex][Inequality Comparison] Rewrite:                                                                 [tex]\displaystyle n(8n^3 - 2n^2 + 19) \geq 6 + 3n^4[/tex][Inequality Comparison] Simplify:                                                                 [tex]\displaystyle 8n^4 - 2n^3 + 19n \geq 6 + 3n^4 \ \checkmark \text{true}[/tex]

∴ the sum  [tex]\displaystyle \sum^{\infty}_{n = 19} \frac{8n^3 - 2n^2 + 19}{6 + 3n^4}[/tex]  is divergent by DCT.

Step 3: Apply LCT

Define:                                                                                                           [tex]\displaystyle a_n = \frac{8n^3 - 2n^2 + 19}{6 + 3n^4}, \ b_n = \frac{1}{n}[/tex]Substitute in variables [LCT]:                                                                       [tex]\displaystyle \lim_{n \to \infty} \frac{8n^3 - 2n^2 + 19}{6 + 3n^4} \cdot n[/tex]Simplify:                                                                                                         [tex]\displaystyle \lim_{n \to \infty} \frac{8n^4 - 2n^3 + 19n}{6 + 3n^4}[/tex][Limit] Evaluate [Coefficient Power Rule]:                                                   [tex]\displaystyle \lim_{n \to \infty} \frac{8n^4 - 2n^3 + 19n}{6 + 3n^4} = \frac{8}{3}[/tex]

∴ Because  [tex]\displaystyle \lim_{n \to \infty} \frac{a_n}{b_n} \neq 0[/tex]  and the sum  [tex]\displaystyle \sum^{\infty}_{n = 19} a_n[/tex]  diverges by DCT,  [tex]\displaystyle \sum^{\infty}_{n = 19} \frac{8n^3 - 2n^2 + 19}{6 + 3n^4}[/tex]   also diverges by LCT.

Topic: AP Calculus AB/BC (Calculus I/I + II)

Unit: Convergence Tests (BC Only)

Book: College Calculus 10e

Put the following equation of a line into slope-intercept form, simplifying all
fractions.
9x – 15y = 135

Answers

Answer:

y=3/5x-9

Step-by-step explanation:

9x – 15y = 135

Subtract 9x from each side

9x -9x – 15y =-9x+ 135

-15y = -9x +135

Divide each side by -15

-15y/-15 = -9x/-15 +135/-15

y=3/5x-9

21. Gabe Amodeo, a nuclear physicist, needs 80 liters of a 30% acid solution. He currently has a 20% solution and a 60%
solution. How many liters of each does he need make the needed 80 liters of 30% acid solution?
Gabe needs
liters of the 20% solution.
He also needs
liters of the 60% solution.

Answers

Let x be the amount (in liters) of 20% solution that Gabe uses, and y the amount (also in L) of the 60% solution.

He needs 80 L of 30% solution, so that

x + y = 80

0.20x + 0.60y = 0.30 (80) = 24

Solve for y in terms of x :

y = 80 - x

Substitute this into the second equation and solve for x :

0.20x + 0.60 (80 - x) = 24

0.20x + 48 - 0.60x = 24

24 = 0.40x

x = 60

Solve for y :

y = 80 - 60

y = 20

Determine the value(s) for which the rational expression -3z+6/6z^2+14z-80 is undefined.

Answers

Answer:

[tex]z= 2 \ and \ z = \frac{-20}{3}[/tex]

Step-by-step explanation:

For the given expression to be undefined, it means that the denominator of the expression must be equal to zero

Hence;

[tex]6z^2+14z-80 = 0[/tex]

On factorizing:

[tex]6z^2+14z-80=0\\3z^2+7z-40 = 0\\3z^2-6z+20z-40 = 0\\3z(z-2)+20(z-2) = 0\\(3z+20)(z-2) =0\\(z-2)=0 \ and \ (3z+20)=0\\z= 2 \ and \ z = \frac{-20}{3}[/tex]

Multiply the complex numbers: (1∕2 + 4i)2
Question 10 options:

A)

–153∕4 + 4i

B)

153∕4 + 8i

C)

–153∕4 + 8i

D)

153∕4 + 4i

Answers

Step-by-step explanation:

153∕4 + 8i is the correct answer

[I'm supposing that you have to find the value of (1/ 2 + 4i)²]

Answer:

[tex] = \frac{ - 63}{4} + 4i[/tex]

Step-by-step explanation:

we must know that

(a + b)² = a² + b² + 2ab

[tex] {( \frac{1}{2} + 4i) }^{2} = { (\frac{1}{2} })^{2} + {(4i)}^{2} + 2 . \frac{1}{2} . 4i[/tex]

[tex] = \frac{1}{4} + 16 {i}^{2} + 4i[/tex]

since i²= -1

[tex] = \frac{1}{4} - 16 + 4i[/tex]

[tex] = \frac{1 - 64}{4} + 4i[/tex]

[tex] = \underline{ \frac{ - 63}{4} + 4i} [/tex]

[I'm also assuming that instead of -153/4 + 4i option A says -63/ 4 + 4i.]

so the answer is option A.

Find m These questions getting hard

Answers

Answer:

the

Step-by-step explanation:

it's fairly easy actually. You just have to use sin

Sudhanshu is solving a system representing a race between two remote control cars. The variable x is defined as time in seconds, and y is the distance in meters from the starting line.

Red car: y = 3 x + 5. Blue car: y = 4 x.

How many solutions should Sudhanshu find?
zero
one
two
infinite

Answers

Answer:

One

General Formulas and Concepts:

Algebra I

Slope-Intercept Form: y = mx + b

m - slope b - y-intercept

Solving systems of equations

Step-by-step explanation:

Step 1: Define

Identify systems

y = 3x + 5

y = 4x

Step 2: Solve

If we compare the 2 lines, we can see that they both have a different slope. If they had the same slope but different y-intercepts, then they would be parallel and have no solution. We can also see that the 2 lines aren't the same. If they were, then they would have infinite solutions.

∴ the systems should have only one solution.

Answer:

B

Step-by-step explanation:

2-[6÷2+{6×1/2+(7/2-3/2)}]​

Answers

Answer:

-6

Step-by-step explanation:

2 - [6 ÷ 2 + {6 × 1/2 + (7/2 - 3/2)}] =

Follow the correct order of operations.

Do one step at a time and copy everything else each time, so you don't lose track of any operation.

= ​2 - [6 ÷ 2 + {6 × 1/2 + 4/2}]

= 2 - [6 ÷ 2 + {6 × 1/2 + 2}]

= 2 - [6 ÷ 2 + {3 + 2}]

= 2 - [6 ÷ 2 + 5]

= 2 - [3 + 5]

= 2 - 8

= -6

Answer:

-6

hope this helps

Step-by-step explanation:

2_(6÷2+(6*1/2+(7/2-3/2))) solve the ones in bracket first

(7/2-3/2)=2

2-(6÷2+(6×1/2+2))

6×1/2+2

6×1/2=3

3+2=5

2-(6÷2+5)

6÷2=3

3+5=8

2-8

=-6

Put the following equation of a line into slope-intercept form, simplifying all
fractions.
5x – 4y = -4

Answers

4y=5x+4
Divid by 4 to make slop intercept form
Y=5/4y +1
Slop =5/4

Answer:

[tex]\boxed {\boxed {\sf y= \frac{5}{4}x+1}}[/tex]

Step-by-step explanation:

We are given the equation of a line and asked to put it into slope-intercept form.

Slope-intercept form is:

[tex]y=mx+b[/tex]

Where:

m= slope b= y-intercept

In order to put the equation into slope-intercept form, we have to isolate the variable y by performing the inverse operation.

[tex]5x-4y= -4[/tex]

5x is being added to -4y. The inverse of addition is subtraction, so subtract 5x from both sides of the equation.

[tex]5x-5x-4y=-4-5x[/tex]

[tex]-4y=-4-5x[/tex]

The variable y is being multiplied by -4. The inverse of multiplication is division. Divide both sides of the equation by -4.

[tex]\frac {-4y}{-4}=\frac{-4-5x}{-4}[/tex]

[tex]y= \frac{-4}{-4}+\frac{-5x}{-4}[/tex]

[tex]y=1+\frac{5}{4}x[/tex]

Rearrange the equation.

[tex]y= \frac{5}{4}x+1[/tex]

The fractions are completely simplified, so this is our final answer.

The equation of the line in slope-intercept form is [tex]\bold {y= \frac{5}{4}x+1}}[/tex].

The slope is 5/4 and the y-intercept is 1.

Malingo read 3/8 of a book on Friday, 1/4 on Saturday and the rest on Sunday. what fraction did he read on Sunday?​

Answers

Answer:

3/8

Step-by-step explanation:

We can write the entire book with the number 1. Now we can write this operation

3/8 + 1/4 + x = 1

3 + 2 + 8x = 8

5 + 8x = 8

8x = 3

x = 3/8

SAT scores are normally distributed with a mean of 1,500 and a standard deviation of 300. An administrator at a college is interested in estimating the average SAT score of first-year students. If the administrator would like to limit the margin of error of the 82% confidence interval to 25 points, how many students should the administrator sample

Answers

Answer:

The appropriate solution is "259".

Step-by-step explanation:

According to the question,

[tex]\sigma = 300[/tex]

[tex]M.E=25[/tex]

At 82% CI,

[tex]\alpha = 0.18[/tex]

Critical value,

[tex]Z_c=1.341[/tex]

Now,

The sample size will be:

⇒ [tex]n=(Z_c\times \frac{\sigma}{E} )^2[/tex]

By substituting the values, we get

      [tex]=(1.341\times \frac{300}{25} )^2[/tex]

      [tex]=(1.341\times 12)^2[/tex]

      [tex]=259[/tex]

From the figure, how many square units are the area of ​​a triangle xwy when yw=zw?
A. 1.84
B. 1.42
C. 0.42
D. 0.84

Answers

Answer:

0.42

Step-by-step explanation:

→ Use Pythagoras to find YZ

√2.5² - 0.7² = 2.4

→ Half the answer to find YW

2.4 ÷ 2 = 1.2

→ Substitute the values into the formula for the area of a triangle

0.5 × 0.7 × 1.2 = 0.42

a truck rental company rents a moving truck for one day by charging $20 plus $0.05 per mile. Write a linear equation that relates the cost C, in dollars, of renting the truck to the number x of miles driven. waht is the cost of renting the truck if the truck is driven 107 miles

Answers

Answer:

The linear equation that relates the cost C, in dollars, of renting the truck to the number x of miles driven is 0.05*x + 20 and the cost of renting the truck if the truck is driven 107 miles is 25.35.

Step-by-step explanation:

A linear function is a polynomial function of the first degree that has the form:

f (x) = y = m*x + b

where m is the slope of the function and b is the y-intercept.

The graph of a linear function is always a line.

A truck rental company rents a moving truck for one day by charging $20 plus $0.05 per mile. So, the number of miles travel is represented by "x"  and the cost per mile is represented by "c". The y-intercept is the starting cost at zero miles or $20.  The slope is the rate per mile or $0.05. Then:

c= 0.05*x + 20

If the truck is driven 107 miles, then:

c= 0.05* 107 + 20

Solving:

c= 25.35

So, the linear equation that relates the cost C, in dollars, of renting the truck to the number x of miles driven is 0.05*x + 20 and the cost of renting the truck if the truck is driven 107 miles is 25.35.

please help, will give brainliest!!!

Answers

Answer:

f^-1(x) = sqrt(x+4)

Step-by-step explanation:

y = x^2 -4

Exchange x and y

x = y^2 -4

Add 4 to each side

x+4 = y^2

Take the square root of each side

sqrt(x+4) = y

f^-1(x) = sqrt(x+4)

Answer:

f^-1(x) = sqrt(x+4)

Step-by-step explanation:

...............................................................

Answers

You got a question...or..?

Subtract 7 pounds 3 ounces from 10 pounds

Answers

(10 pounds) - (7 pounds 3 ounces) =
2.8125 pounds

Refer to the values described below, then identify which of the following is most appropriate: discrete random variable, a. Responses to the survey question "How many pets do you have?" b. Exact heights of the next 100 babies born in a region c. Responses to the survey question "What is your eye color?" d. Exact foot length of humans e. Number of people in families a. Since the outcomes are b. Since the outcomes are countable, this is this is a discrete random variable. random variable.

Answers

Answer:

Exact heights of the next 100 babies born in a region.

Step-by-step explanation:

A discrete random variable involves two key factors ; discrete and randomness ; Hence, a discrete random variable should have a finite or countable Number of outputs or values. It should also stem from a random procedure. Here, the height of the next hundred babies is a random procedure as the next 100 babies in the region are unknown until Given birth too and as such all pregnant women have the chance of having their babies among. Since, we are dealing with exact height values which are countable (100), then we this is a discrete random variable.

Other Questions
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