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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
9.3 t-Interval to Compare Two Population Means: Independent Samples (Equal Variances)
A parent theorized that his daughter spent more time on her cell phone than his son. He randomly selected 27 calls made by his son and 25 call made by his daughter from his past phone records. His son’s calls had an average length of 23.5 minutes with a variance of 28 minutes. While his daughter’s calls had an average length of 36.1 minutes with a variance of 35 minutes. Find the 99% confidence interval for the true mean difference between the length of calls made by his son and his daughter (Assume equal variances). Is there a significant difference?
STATS1
STATS2
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