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
Ghella [55]
3 years ago
9

A supervisor records the repair cost for 14 randomly selected refrigerators. A sample mean of $79.20 and standard deviation of $

10.41 are subsequently computed. Determine the 90% confidence interval for the mean repair cost for the refrigerators. 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:
Nitella [24]3 years ago
5 0

Answer:

( $74.623, $83.777)

The 90% confidence interval is = ( $74.623, $83.777)

Critical value at 90% confidence = 1.645

Step-by-step explanation:

Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.

The confidence interval of a statistical data can be written as.

x+/-zr/√n

Given that;

Mean x = $79.20

Standard deviation r = $10.41

Number of samples n = 14

Confidence interval = 90%

Using the z table;

The critical value that should be used in constructing the confidence interval.

z(α=0.05) = 1.645

Critical value at 90% confidence z = 1.645

Substituting the values we have;

$79.20+/-1.645($10.42/√14)

$79.20+/-1.645($2.782189528308)

$79.20+/-$4.576701774067

$79.20+/-$4.577

( $74.623, $83.777)

The 90% confidence interval is = ( $74.623, $83.777)

You might be interested in
You have a $20 coffee card. Each time you go there, you spend $1.25. The equation y = -1.25 x + 20 represents how much you have
Lubov Fominskaja [6]

it would be 16 times, hope this helps

8 0
3 years ago
Read 2 more answers
HELP ASSSAPPP WITH THIS QUESTION!!!
Gekata [30.6K]
D.d=24%
d.r=29%
d.t=53%
r.d=24%
r.r=24%
r.t=47%
t.d=47%
t.r=53%
t.t=100%
Just take the numbers and divide them over the total amount which in this caase is 51.
5 0
3 years ago
Which ordered pair represents the y-intercept of the graph of the equation y= -4x - 7
oksian1 [2.3K]

Answer:

(0,-7)

Step-by-step explanation:

7 0
3 years ago
3.5 pounds $1.19 per pound how much did she spend? to the nearest cent
Snezhnost [94]
4.16 I think if I did the math right
6 0
3 years ago
Read 2 more answers
A painting has an area of 108 square inches. The dimensions of the painting are 12 and x + 3. What is the perimeter of the paint
dmitriy555 [2]

Answer:

42 inches square

Step-by-step explanation:

x=6

108/12=9

9-3=6

12+12+9+9=42

6 0
3 years ago
Read 2 more answers
Other questions:
  • In the game of​ "Between," two cards are dealt from a standard deck and not replaced. You then pick a third card from the deck.
    13·1 answer
  • A truck needs 7 gallons of fuel to travel 56 miles. Can the truck travel 48 miles with 6 gallons of fuel? Explain.
    13·2 answers
  • Selena bought 3.75 lb of meat for $4.64 per pound what is the total cost of the meat
    13·2 answers
  • Mr. Johansen is cutting construction paper for an art project. He has 24 students, and six pieces of construction paper. How muc
    8·1 answer
  • Jada wants to buy a picture frame that costs $6.48. She has $3.50.
    13·1 answer
  • What are the subsets
    15·2 answers
  • Equations for review solve each equation 1.) -8+n=7
    6·1 answer
  • What is 65% of 160.
    5·2 answers
  • La matemática financiera experimentó grandes avances con la creación de la banca y los negocios creados por los emprendedores. E
    8·1 answer
  • Which equation represents: three times the difference of a number and five is nine
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!