CarMD reports that the cost of repairing a hybrid vehicle is falling even while typical repairs on conventional vehicles are get-ting more expensive. The most common hybrid repair, replacing the hybrid inverter assembly, had a mean repair cost of $ 3,927 in 2012. Industry experts suspect that the cost will continue to de-crease given the increase in the number of technicians who have gained expertise on fixing gas– electric engines in recent months. Suppose a sample of 100 hybrid inverter assembly repairs completed in the last month was selected. The sample mean repair cost was $ 3,800 with the sample standard deviation of $ 500.   Is there evidence that the population mean cost is less than $ 3,927? (Use a 0.05 level of significance.)   Determine the p- value and interpret its meaning.

Linear Algebra: A Modern Introduction
4th Edition
ISBN:9781285463247
Author:David Poole
Publisher:David Poole
Chapter7: Distance And Approximation
Section7.3: Least Squares Approximation
Problem 31EQ
icon
Related questions
Topic Video
Question

CarMD reports that the cost of repairing a hybrid vehicle is falling even while typical repairs on conventional vehicles are get-ting more expensive. The most common hybrid repair, replacing the hybrid inverter assembly, had a mean repair cost of $ 3,927 in 2012. Industry experts suspect that the cost will continue to de-crease given the increase in the number of technicians who have gained expertise on fixing gas– electric engines in recent months. Suppose a sample of 100 hybrid inverter assembly repairs completed in the last month was selected. The sample mean repair cost was $ 3,800 with the sample standard deviation of $ 500.

 

  1. Is there evidence that the population mean cost is less than $ 3,927? (Use a 0.05 level of significance.)

 

  1. Determine the p- value and interpret its meaning.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 4 steps with 1 images

Blurred answer
Knowledge Booster
Hypothesis Tests and Confidence Intervals for Means
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Linear Algebra: A Modern Introduction
Linear Algebra: A Modern Introduction
Algebra
ISBN:
9781285463247
Author:
David Poole
Publisher:
Cengage Learning
Glencoe Algebra 1, Student Edition, 9780079039897…
Glencoe Algebra 1, Student Edition, 9780079039897…
Algebra
ISBN:
9780079039897
Author:
Carter
Publisher:
McGraw Hill
Big Ideas Math A Bridge To Success Algebra 1: Stu…
Big Ideas Math A Bridge To Success Algebra 1: Stu…
Algebra
ISBN:
9781680331141
Author:
HOUGHTON MIFFLIN HARCOURT
Publisher:
Houghton Mifflin Harcourt