Answers to the Review questions from Homework 5

Review Exercise Answers (Chapter 23)

1. (a) The sum of 400 draws will be about 400 x 100 = 40,000 give or take SQRT(400) x 20 = 400 or so. The chance is almost 100%.
(b) The range is "expected value +/- 1 standard error" so the chance is about 68%

2. (a) True. This is the SE.
(b) True. The 68% confidence interval is "sample average +/- 1 Standard error for average"
(c) False. See p. 417. Please don't confuse SE and SD.