A consumer affairs investigator records the repair cost for 4 randomly selected washers. A sample mean of $52.63 and standard deviation of $22.01 are subsequently computed. Determine the 80% confidence interval for the mean repair cost for the washers. Assume the population is approximately normal. Step 2 of 2 : Construct the 80% confidence interval. Round your answer to two decimal places.

Answers

Answer 1

Answer:

The 80% confidence interval for the mean repair cost for the washers is between $34.60 and $70.66.

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 4 - 1 = 3

80% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 3 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.8}{2} = 0.9[/tex]. So we have T = 1.638

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 1.638\frac{22.01}{\sqrt{4}} = 18.03[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 52.63 - 18.03 = $34.60

The upper end of the interval is the sample mean added to M. So it is 52.63 + 18.03 = $70.66.

The 80% confidence interval for the mean repair cost for the washers is between $34.60 and $70.66.


Related Questions

Rule 1: Add 7 starting from 0. Rule 2: Multiply by 2 starting from 8. Select the option that correctly shows the first 5 terms of each sequence.
Question 5 options:

First sequence: 0, 6, 12, 18, 24 and second sequence: 0, 8, 16, 32, 64

First sequence: 0, 7, 14, 21, 28 and second sequence: 8, 16, 32, 64, 128

First sequence: 0, 7, 14, 21, 28 and second sequence: 8, 14, 28, 56, 112

First sequence: 14, 21, 28, 35, 42 and second sequence: 8, 16, 32, 64, 128

Answers

Answer:

First sequence: 0, 7, 14, 21, 28 and second sequence: 8, 16, 32, 64, 128

Answer:

First sequence: 0, 7, 14, 21, 28 and second sequence: 8, 16, 32, 64, 128

Step-by-step explanation:

Solve for x.
4x + 6
4x + 6
x = [?]

Answers

Answer:

21

Step-by-step explanation:

4x+6+4x+6=180

8x+12=180

8x=168

x=21

Answer:

X=21

Step-by-step explanation:

Well since its just a right angle you really gotta only solve for one since their their the same things.

4x+6=90

Solve the equation

x=21

Even if you do the two together with 180, same thing.

Devin measured his basketball rim. The radius of the rim is 6 inches. What is the circumference of the rim?

Answers

the circumstance of the rim is 37.6

If I paid $2.50 in taxes on a $45 item, what percentage rate of taxes did I pay?

Answers

Answer:

47.05

Step-by-step explanation:

12345678910^#3:##;$$;$%#;#<÷&÷#7#;;^#

How many lines of symmetry does the figure below have?

Answers

Answer:

C

Step-by-step explanation:

there are 4 of the exact same line going in 4 directions

Annual starting salaries for college graduates with degrees in business administration are generally expected to have a population standard deviation of $3,000. Assume that a 95% confidence interval estimate of the population mean annual starting salary is desired. How large a sample should be taken if the desired margin of error is (a) [1 pt] $500

Answers

Answer:

A sample of 139 should be taken.

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

Population standard deviation of $3,000.

This means that [tex]\sigma = 3000[/tex]

How large a sample should be taken if the desired margin of error is $500?

A sample of n is needed.

n is found when M = 500. So

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]500 = 1.96\frac{3000}{\sqrt{n}}[/tex]

[tex]500\sqrt{n} = 1.96*3000[/tex]

Dividing both sides by 500

[tex]\sqrt{n} = 1.96*6[/tex]

[tex](\sqrt{n})^2 = (1.96*6)^2[/tex]

[tex]n = 138.3[/tex]

Rounding up:

A sample of 139 should be taken.

2x1+0x2+3x3=3
4x1-3x2+7x3=5
8x1-9x2+15x3=10
solve the system using Gaussian or Gauss-Jordan elimination

Answers

[1] … … 2x₁ + 0x₂ + 3x₃ = 3

[2] … … 4x₁ - 3x₂ + 7x₃ = 5

[3] … … 8x₁ - 9x₂ + 15x₃ = 10

Since [1] is already free of x₂, you might as well start by eliminating x₂ from the other two equations. Add -3 times [2] to [3] :

-3 (4x₁ - 3x₂ + 7x₃) + (8x₁ - 9x₂ + 15x₃) = -3 (5) + 10

-12x₁ + 9x₂ - 21x₃ + 8x₁ - 9x₂ + 15x₃ = -15 + 10

-4x₁ - 6x₃ = -5

[4] … … 4x₁ + 6x₃ = 5

Now eliminate x₃ in [1] and [4]. Add -2 times [1] to [4] :

-2 (2x₁ + 3x₃) + (4x₁ + 6x₃) = -2 (3) + 5

-4x₁ - 6x₃ + 4x₁ + 6x₃ = -6 + 5

0 = -1

which is a contradiction. This means the system has no solution.

A ball is dropped from the top of a building that is 250 feet tall. The
height h of the ball in feet after t seconds is modeled by the function h =
- 16t2 + 250. How long will it take for the ball to reach a height of 75
feet? Round to the nearest tenth.

Answers

hi

-16t²+250 = 75

-16t² = 75 -250

-16t² = -175

  t² = -175 /-16

 t² = 175/16

Here there si two solutions :  t = [tex]\sqrt{175/16}[/tex]   and  t =  - [tex]\sqrt{175/16}[/tex]

However, as time cannot rewind,  we will  keep only positive solution

So t = [tex]\sqrt{175/16}[/tex]

   

in seconds  it will be  :  3.3 seconds

1) you deposit $2,300 in a bank account. find the balance after 5 years for each of the following situations: is) the account pays 2.5% annual interest compounded monthly.

Answers

Answer:

Well, After 5 years No interest you'd still have only 2,300 dollars in the bank.

But 5 years with interest you'd have 5750$ in the bank.

Step-by-step explanation:

With no interest, their is nothing added to your bank account, if you don't take anything away from it either then you'd still have the exact same amount.

With 2.5% monthly interest you'd get 3250$ because...5years * 12 months = 60 months...60 months * 2.5% = 150%...2,300$ + 150% = 5750$.

Using the graph, determine the coordinates of the vertex of the parabola.

Answers

I don’t know for sure, but I think the vertex is (-5, 9)

If it’s wrong, hopefully this bobcat will make your day better

y = 4x + 8 when x = 3y

Answers

Answer:

-8/11

Step-by-step explanation:

what are you trying to isolate

Find the a. Median b. Median c. Mode and d. Range of the following scores 60, 70, 90, 70, 80, 65, 95, 80, 100, 60

Answers

Answer:

median-75

mode-70

range-40

mean-77

Step-by-step explanation:

Mia, Eli, and Doug are
comparing the sizes of
their movie collections.
Ell has twice as many
movies as Mia. Doug has
14 more movies than
Mia. Write an expression
to represent the total
movies the friends have.

Answers

Answer:

4m + 14

Step-by-step explanation:

m = # movies Mia has

2m = # movies Eli has

14 + m = # movies Doug has

Total:  m + 2m + 14 + m = 4m + 14

Ten field hockey teams are competing in a tournament. Only the top three teams will be recognized as the first place, second place and third place winners. In how many ways could the ranking of the top three teams occur?

Answers

Answer:

The ranking of the top three teams could occur in 720 ways.

Step-by-step explanation:

The order in which the teams are ranked is important, that is, for example, Oilers, Flames and Canucks is a different outcome of Oilers, Canucks and Flames. This means that the permutations formula is used to solve this question.

Permutations formula:

The number of possible permutations of x elements from a set of n elements is given by the following formula:

[tex]P_{(n,x)} = \frac{n!}{(n-x)!}[/tex]

In how many ways could the ranking of the top three teams occur?

Three teams from a set of 10. So

[tex]T = P_{(10,3)} = \frac{10!}{7!} = 720[/tex]

The ranking of the top three teams could occur in 720 ways.

The Smith family is building a deck that is 200 square feet in area. What are the
possible lengths and widths the deck could have?

Answers

So any configuration the deck could be in
I am guessing in whole numbers but any and every number could work. so divide 200( which is gotten by length times width ) by numbers starting with one... to find the possible deck sizes...

1by200feet

2by100feet

4by50feet

5by40feet

8by25feet

10by20feet

A mountain climber started at 150 feet below sea level. What would he need to climb to so that his starting spot and his ending spot were opposites?

Answers

Answer:

Your answer is 24.333.

Step-by-step explanation:

..If you round this, it would be 24 or 24.3. you get this answer by doing 3650 divided by 150.

Manny buys hot dog buns for a cookout. he needs 30 buns and he buys bags of 8 buns. how many bags does manny need?

Answers

Answer:4

Step-by-step explanation:

30÷8=3.75

3.75=4

Manny need 4 bags.

Can someone please help me I am a no brain and very dum
Suppose 12% of students surveyed said they have tried riding a zip line.

a. How many would say they have tried riding a zip line if 100 students were surveyed.

Answers

200$ because that’s the percent

GIVING OUT BRAINLIEST TO WHOEVER CAN PROVIDE THE CORRECT ANSWER !! Asap

Answers

it is d, because if you use the rule sine is soa, so it is just the opposite and adjacent angles

the area of a square room is 144square metres what is the perimeter of the room​

Answers

Answer:

the answer is 48

Step-by-step explanation:

12×12=144

4×12=48

A jewerler had a fixed amount of gold

Answers

Answer:

ohhhhh and who is the jeweler

PLS HELP WILL GIVE BRAINLIEST

Malcolm's net worth is $3,475. His liabilities are $7,650.
What is the total
value of his assets?
A.) 3,475
B.) 7,640
C.) 10,005
D.) 11,115

Answers

i think it’s c or d i believe but i’m not 100% sure

The solution is, D.) 11,115 is the total value of his assets.

What is addition?

Addition is a way of combining things and counting them together as one large group. ... Addition in math is a process of combining two or more numbers.

here, we have,

given that,

Malcolm's net worth is $3,475.

His liabilities are $7,650.

now, we have,

the total value of his assets is:

we just have to add them.

$3,475 + $7,650

=11125

Hence, The solution is, D.) 11,115 is the total value of his assets.

To earn more on addition click:

brainly.com/question/29560851

#SPJ2

I NEED HELP CLICK HERE PLEASE

Answers

Answer:

A- II

B- I

C- III

D- IV

Step-by-step explanation:

Need help

1. 15% of what number is 6?

2. 25 is 10% of what number

3. 49 is 35% of what number

4. What is 310% of 65

Thanks

Answers

Answer:

1. 40

2. 40

3. 140

4. 210.5

I tried, hope this helps :)

Find the interquartile range of the data. 4,6,4,2,9,1,12,7

Answers

Answer:

5

Step-by-step explanation:

1.) Order the numbers from least to greatest (1,2,4,4,6,7,9,12) then find the HIGHEST and LOWEST #.

2.)  Find the number in the very middle, which would be 4 and 6. Since it's not one number, add them both together and divide by 2 (4+6=10, 10/2=5). This will be your MEDIAN.

3.) Similar to step 2, find the number in the middle of the median and lowest number. Ignore the median in this. Since it's 2 numbers again, add both together and divide by 2 (2+4=6, 6/2 = 3, making the first interquartile 3).

4.) Repeat step 3, but instead of finding the number in the middle of the median and lowest number, use the highest number instead of the lowest. Since this also happens to be 2 numbers, repeat the same step of adding the numbers and then dividing by 2 (7+9=16, 16/2=8, making the second interquartile 8).

5.) Now, subtract both interquartiles. This should give you your answer (5).

A 12-pound bag weighs more than a 200-ounce bag. True or false

Answers

Answer:

false

Step-by-step explanation:

200oz= 12.5 pounds

Answer:

false

Step-by-step explanation:

12 pound=192 ounces

Taylor had a bag of 28 marbles. 5 red, 9 blue, 8 yellow, and 6 black. If Taylor pulled out a yellow one and DID NOT put it back in. What is the probability of pulling out a blue marble (SIMPLIFY YOUR FRACTION). /

Answers

Answer:

The probability of pulling out a blue marble is 33.3%.

Step-by-step explanation:

Given that Taylor had a bag of 28 marbles, which were 5 red, 9 blue, 8 yellow, and 6 black, if Taylor pulled out a yellow one and did not put it back in, to determine what is the probability of pulling out to blue marble the following calculation must be carried out:

28 - 1 = 27

9/27 = X

0.333 = X

0.333 = 33.3%

Therefore, the probability of pulling out a blue marble is 33.3%.

PLEASE HELP! WILL GIVE BRAINLIEST! After substituting, what is the first step when evaluating 4y+9 when y=82 O Add 4 and 9. O Multiply 8 by 4. O Divide 9 by 7 O Divide 4 by 7.​

Answers

Answer:

The answer is c

Step-by-step explanation:


Please help!!
Find the coordinates of the vertex of the following parabola algebraically. Write your
answer as an (x, y) point.
y = 4x + 56x + 192

Answers

Answer:

 The vertex of the parabola   = (-7 , -4)  

Step-by-step explanation:

Step(i):-

Given that the parabola  y = 4 x² + 56 x +192

                                 y = 4 (x² + 14 x + 48 )

                                 y = 4 ( x² + 2 ×  7 (x) + 49-1)

                                 y = 4 ( x² + 2 ×  7 (x) + 49)- 4

we apply the formula

(a +b)² = a² + 2ab + b²

                                y = 4 ( x + 7 )² - 4

Step(ii):-

The general form of the parabola in algebraically

                              y = a ( x-h)² +k

The equation

                          y = 4 ( x + 7 )² - 4

                          y = 4 ( x-(-7))² - 4

  The vertex of the parabola (h,k) = (-7 , -4)  

Final answer:-

The vertex of the parabola  = (-7 , -4)  

If AB = 4x +20 and DC = 10x - 16 find x and AB

Answers

Answer: X=dc/10+8/5   X=AB/4 -5 hope it helps

Step-by-step explanation:

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