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Confidence Intervals and Hypothesis Testing: Exercise 5.11b
tanwzwz Sep 13, 2016 ReplyFlag
Hi there, it's great to have such a textbook for my self-study. I was going through the exercises and I'm wondering why the critical value is taken to be 2.093 instead of 1.729, since it's a 1-tailed test? I'm not sure if it's a misunderstanding on my part.

OpenIntro book, 3rd ed.

Exercise 5.11b on page 259
Answer on page 416.
podleska Jan 16 ReplyFlag
Confidence intervals are almost always done as 2-sided. Think of the confidence interval as just an interval estimate for the mean number of years of piano lessons that children in the city take. (So the confidence interval wouldn't be different even if someone wanted to test a different claim.)
A hypothesis test has the goal of testing a specific claim, which is that the average child takes at least 5 years of lessons.
podleska Jan 16 ReplyFlag
Confidence intervals are almost always done as 2-sided. Think of the confidence interval as just an interval estimate for the mean number of years of piano lessons that children in the city take. (So the confidence interval wouldn't be different even if someone wanted to test a different claim.)
A hypothesis test has the goal of testing a specific claim, which is that the average child takes at least 5 years of lessons.

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