CNNBC recently reported that the mean annual cost of auto insurance is 972 dollars. Assume the standard deviation is 102 dollars. You will use a simple random sample of 58 auto insurance policies. Find the probability that a single randomly selected policy has a mean value between 977.4 and 997.4 dollars. P(977.4 < X < 997.4) =  Find the probability that a random sample of size n=58 has a mean value between 977.4 and 997.4 dollars. P(977.4 < ¯x < 997.4) =  Enter your answers as numbers accurate to 4 decimal places.

A First Course in Probability (10th Edition)
10th Edition
ISBN:9780134753119
Author:Sheldon Ross
Publisher:Sheldon Ross
Chapter1: Combinatorial Analysis
Section: Chapter Questions
Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...
icon
Related questions
Question

CNNBC recently reported that the mean annual cost of auto insurance is 972 dollars. Assume the standard deviation is 102 dollars. You will use a simple random sample of 58 auto insurance policies.

Find the probability that a single randomly selected policy has a mean value between 977.4 and 997.4 dollars.
P(977.4 < X < 997.4) = 

Find the probability that a random sample of size n=58 has a mean value between 977.4 and 997.4 dollars.
P(977.4 < ¯x < 997.4) = 

Enter your answers as numbers accurate to 4 decimal places.

Expert Solution
Step 1

Let us denote: X=the mean annual cost of auto insurance X follows a normal distribution with mean=972 and standard deviation = 102n=sample size=58X¯ follows a normal distribution with mean=972 and standard deviation =10258=13.3932561517

Step 2

A) The probability that a single randomly selected policy has a mean value between 977.4 and 997.4 dollars is:P(977.4 < X < 997.4) =P977.4-972102<Z<997.4-972102=P(0.0529411764706<Z<0.249019607843)=0.0772

 

steps

Step by step

Solved in 3 steps

Blurred answer
Knowledge Booster
Point Estimation, Limit Theorems, Approximations, and Bounds
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, probability and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
A First Course in Probability (10th Edition)
A First Course in Probability (10th Edition)
Probability
ISBN:
9780134753119
Author:
Sheldon Ross
Publisher:
PEARSON
A First Course in Probability
A First Course in Probability
Probability
ISBN:
9780321794772
Author:
Sheldon Ross
Publisher:
PEARSON