For each scenario below, decide if it would be appropriate to use (1) Critical z-values or (2) Critical t-values to find the confidence interval. A certain test preparation course is designed to help students improve their scores on the LSAT exam. A mock exam is given at the beginning and end of the course to determine the effectiveness of the course. The following measurements are the net change in 5 students' scores on the exam after completing the course:13, 19, 22, 15, 29Using these data, construct a 90% confidence interval for the average net change in a student's score after completing the course. Assume the population is approximately normal. A manager records the repair cost for 6 randomly selected TVs. A sample mean of $67.87 and standard deviation of $28.03 are subsequently computed. Determine the 95% confidence interval for the mean repair cost for the TVs. Assume the population is approximately normal. A survey of 61 randomly selected homeowners finds that they spend a mean of $73 per month on home maintenance. Construct a 99% confidence interval for the mean amount of money spent per month on home maintenance by all homeowners. Assume that the population standard deviation is $11 per month.

Solution To find the confidence interval we will use Excel According to the guidelines we solve only first question when questions are different

Answered: For each scenario below, decide if it…

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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Question

For each scenario below, decide if it would be appropriate to use (1) Critical z-values or (2) Critical t-values to find the confidence interval.

	A certain test preparation course is designed to help students improve their scores on the LSAT exam. A mock exam is given at the beginning and end of the course to determine the effectiveness of the course. The following measurements are the net change in 5 students' scores on the exam after completing the course: 13, 19, 22, 15, 29 Using these data, construct a 90% confidence interval for the average net change in a student's score after completing the course. Assume the population is approximately normal.
	A manager records the repair cost for 6 randomly selected TVs. A sample mean of $67.87 and standard deviation of $28.03 are subsequently computed. Determine the 95% confidence interval for the mean repair cost for the TVs. Assume the population is approximately normal.
	A survey of 61 randomly selected homeowners finds that they spend a mean of $73 per month on home maintenance. Construct a 99% confidence interval for the mean amount of money spent per month on home maintenance by all homeowners. Assume that the population standard deviation is $11 per month.