This preview shows page 1. Sign up to view the full content.
Unformatted text preview: Unit Review  TEST 3  Statistics 1. Replacement times for CD players are normally distributed with a mean of 7.1 years and a standard deviation of 1.4 years. A) Find the probability that a randomly selected CD player will have a replacement time less than 8.0 years . B) If 45 CD players are randomly selected, how many of them would you expect to have a replacement time less than 8.0 years. C) If 45 CD players are randomly selected, find the probability that they will have a mean replacement time greater than 7.0 years . D) Find the probability that 45 randomly selected CD players will have a mean replacement time between 6.8 years and 7.2 years. 2. A sample consists of 75 TV sets purchased several years ago. The replacement times of those TV sets have a mean of 8.2 years and a standard deviation of 1.1 years. A) Construct a 95% confidence interval for the mean replacement time of all TV sets from that era. B) Construct a 86% confidence interval for the mean replacement time of all TV sets from that era.that era....
View
Full
Document
This note was uploaded on 03/19/2011 for the course STAT 101 taught by Professor Hughes during the Spring '11 term at Andrews Univeristy.
 Spring '11
 Hughes
 Statistics, Probability, Standard Deviation

Click to edit the document details