In each of Exercises, use the Wilcoxon signed-rank test to perform the required hypothesis test. Global Warming? During the late 1800s, Lake Wingra in Madison, Wisconsin, was frozen over an average of 124.9 days per year. A random sample of eight recent years provided the following data on numbers of days that the lake was frozen over. 103 80 79 135 134 77 80 111 At the 5% significance level, do the data provide sufficient evidence to conclude that the average number of ice days is less now than in the late 1800s?

A psychologist would like to know whether the season (autumn, winter, spring, and summer) has any consistent effect on people's sexual activity. In the middle of each season, a psychologist selects a random sample of 22 students. Each individual is given a sexual activity questionnaire. A one-factor ANOVA was used to analyze these data. Complete the following ANOVA summary table (a = 0.02). Round your answers to three decimal places, if necessary. Source Between Within Total SS 867.72 df MS F 2.98 P-value

The home run percentage is the number of home runs per 100 times at bat. A random sample of 43 professional baseball players gave the following data for home run percentages.

In a population-based cohort study, an entire community was interviewed regarding smoking habits and then followed for one year. Upon ascertainment of all lung cancer deaths, the investigator obtained the following data:     Number of Individuals Lung Cancer Deaths Smokers 24,500 15 Nonsmokers 10,500 2   Calculate the risk difference per 100,000 per year. Round to the tenth decima