Chapter 21, Problem 20E

Wind speed, part II In Exercise 18, we saw summary statistics for wind speeds at two sites near each other, both being considered as locations for an electricity-generating wind turbine. The data, recorded every 6 hours for a year, showed each of the sites had a mean wind speed high enough to qualify, but how can we tell which site is best? Here are some displays:

1. a) The boxplots show outliers for each site, yet the histogram shows none. Discuss why.
2. b) Which of the summaries would you use to select between these sites? Why?
3. c) Using the information you have, discuss the assumptions and conditions for paired t inference for these data. (Hint: Think hard about the independence assumption in particular.)