1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
PIT_PIT [208]
4 years ago
5

A manager records the repair cost for 4 randomly selected stereos. A sample mean of $82.64 and standard deviation of $14.32 are

subsequently computed. Determine the 90% confidence interval for the mean repair cost for the stereos. Assume the population is approximately normal. Step 1 of 2 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.
Mathematics
1 answer:
zysi [14]4 years ago
6 0

Answer:

CI = (70.861 , 94.418)

Step-by-step explanation:

In order to determine the 90% confidence interval you use the following formula (for a population approximately normal):

CI=(\overline{x}-Z_{\alpha/2}\frac{\sigma}{\sqrt{n}},\overline{x}+Z_{\alpha/2}\frac{\sigma}{\sqrt{n}})    (1)

\overline{x}: mean = 82.64

σ: standard deviation = 14.32

n: sample = 4

α: tail area = 1 - 0.9 = 0.1

Z_α/2 = Z_0.05: Z factor =  1.645

You replace these values and you obtain:

Z_{0.05}(\frac{14.32}{\sqrt{4}})=(1.645)(\frac{14.32}{\sqrt{4}})=11.778

The confidence interval will be:

CI=(82.64-11.778,82.64+11.778)=(70.861,94.418)

The 90% confidence interval is (70.861 , 94.418)

You might be interested in
−4x+35&gt;2<br> Whats the innequality
geniusboy [140]

-4x + 35 > 2

Subtract 35 from both sides:

-4x> -33

Divide both sides by -4:

X > -33 s -4

Because you are dividing the inequality. Y a negative value, reverse the inequality sign.

X < 33/4

7 0
4 years ago
Find the volume of the given shape. Round your answer to the nearest<br> hundredth if necessary
xz_007 [3.2K]

Answer:

volume of sphere =4/3πr^3=4/3*22/7*6*6*6=905.14m^3

4 0
3 years ago
A rectangle has an area of 54 square inches and a length of 6 in what is the width in inches of the rectangle?​
Arada [10]

\mathfrak{\huge{\orange{\underline{\underline{AnSwEr:-}}}}}

Actually Welcome to the Concept of the Areas and Volumes.

We know that, Area of a Rectangle = length * Width.

Since,here Length = 6 inch and Area = 54 square inches,

==> Width = Area / length

==> Width = 54/6

=> Width = 9 inches.

Hence the width of the rectangle is 9 inches.

5 0
3 years ago
Which of the following is greater than 4.3 × 10^9
Aleonysh [2.5K]

Answer:C or D


Step-by-step explanation:


6 0
3 years ago
Read 2 more answers
Solve the equation. -15=a/5 <br> A. a= -3<br> B. a= -20<br> C. a= -10<br> D. a= -75
kap26 [50]
-15=a/5
well first you would multiply by each side, with a result of 
-75=a

so D
8 0
3 years ago
Read 2 more answers
Other questions:
  • You're flying from Joint Base Lewis-McChord (JBLM) to an undisclosed location 125 km south and 135 km east. Mt. Rainier is locat
    12·1 answer
  • What is the probability of selecting a cherry piece? Write answer as a reduced fraction.
    14·1 answer
  • Let point C be between V and W on . Given that VW = 61, VC = z + 13, and CW = z + 8, solve for .
    14·1 answer
  • Find the volume of the box.
    7·1 answer
  • Mrs.suarez cut a pizza into 8 equal slices.each person in her family ate 2 slices .if there are 3 people in her family,what frac
    6·2 answers
  • Answer is due in 1 hour!
    6·1 answer
  • A grocery store sells tangerines in 2/5 kg bags. A customer bought 4 kg of tangerines for a school party. How many bags did he b
    7·1 answer
  • The beginning value is 5 and its value is 3 units smaller at each stage. Equation:
    12·2 answers
  • Rewrite the logarithmic expression as the sum and difference of logarithms. If exponents may be written as the coefficient of a
    13·1 answer
  • Please help !!! I will give 20 points to the correct answer!!
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!