Enjoy learning Statistics Online! Please be sure to share and subscribe to our YouTube channel.

**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

Lecture Examples

Example 143: A product reliability study was conducted on laptops by the company Square Trade Inc. Among 11,500 entry-level laptops (priced between $400 - $1000) followed for one year, 541 malfunctioned. Among 9,300 premium laptops (priced over $1000) followed for one year, 391 malfunctioned. Use a 0.01 significance level to test the claim that the incidence of malfunction is higher for entry-level laptops than it is for premium laptops. Does it seem that spending more money on a laptop will offer you some protection from the inconvenience of a malfunction?