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ASK THE PROFESSOR FORUM

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,

I had another question about Now You Try It! For Section 6.2. If your looking for the average weight between 40 and 41 wouldn't you add the areas 0.4911 and 0.4370, instead of subtracting? Also, can you go through the problem.

Thank you,
Natalie

Question:
It is recommended that backpacks weigh less than 1/4
th of your body weight. The average backpack with four textbooks and school supplies weighs 38.2 pounds with a standard deviation 7.1 pounds. If a randomly selected group of 36 backpacks is
weighed what is the probability that the average weight for the packs is between 40
and 41 pounds?

Posted to STATS 1 on Thursday, November 7, 2013   Replies: 1


Professor Mcguckian
11/07/2013
10:44 AM EST

Hi Natalie,

I have created a video explaining the problem.

 

I hope it answers your questions,

Professor McGuckian

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