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Course Documents

Chapter 1 - Intro

Chapter 2 - Methods for Describing Sets of Data

Chapter 3 - Probability

Chapter 4 - Discrete Random Variables

Chapter 5 - Normal Random Variables

Chapter 6 - Sampling Distributions

Chapter 7 - Confidence Intervals

Chapter 8 - Tests of Hypothesis: One Sample

Chapter 9 - Confidence Intervals and Hypothesis Tests: Two Samples

Sample Exam I: Chapters 1 & 2

Sample Exam II: Chapters 3 & 4

Sample Exam III: Chapters 5 & 6

Sample Exam IV: Chapters 7 & 8

Ask the Professor Forum

Hi professor
For 14.4 question 15: why is the Ho equal to 145 and not greater than or equal to 145? Because in the problem it states that that class should be able to finish exam 3 in less than 145 min.

Thank you

Posted to STATS 2 on Monday, December 2, 2013   Replies: 1

Professor Mcguckian
7:28 PM EST

Hi Shirley,

If the median is 145, then half of the values would be less than 145 (and half would be more). Since the problem states that half the class will finish before 145 minutes, it implies that the median is 145. If the median was less than 145, then more than half of the class would finish before 145 minutes. For example what if the median was 140? Then half of the values would be less than or equal to 140. This means more than half would be less than or equal to 145. That would not be equivalent to what was stated in the claim in this problem.

Hope that helps,

Professor McGuckian 

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