Researchers collected data on the numbers of hospital admissions resulting from motor vehicle crashes, and results are given below for Fridays on the 6th of a month and Fridays on the following 13th of the same month. Use a 0.05 significance level to test the claim that when the 13th day of a month falls on a Friday, the numbers of hospital admissions from motor vehicle crashes are not affected. Friday the 6th: 9. 10 10 3 Friday the 13th: 13 11 13 9. 5 11

Researchers wished to know if they could conclude that two populations of infants differ with respect to mean age at which they walked alone. The following data (ages in months) were collected: Sample from population A: Sample from population B: 9.5, 10.5, 9.0, 9.75, 10.0, 13.0, 10.0, 13.5, 10.0, 9.5, 10.0, 9.75 12.5, 9.5, 13.5, 13.75, 12.0, 13.75, 12.5, 9.5, 12.0, 13.5, 12.0, 12.0 What should the researchers conclude? Let a = .05.

A local park district is planning to build a recreation center. The park district conducted a poll to find out the types of physical activities the local population would be interested in. The poll was based on telephone responses from 1013 randomly selected adults. The table shows the percentages of people who expressed interest in various activities.    Is it reasonable to conclude that 62% expressed interest in either biking or aerobics? A. Yes, because the percentages can always be added in relative frequency tables.   B. No, because the poll is not based on a large-enough number of individuals.   C. Yes, because these categories do not overlap.   D. No, because these categories overlap.   E. No, because the percentages in relative frequencies tables can never be added.

Use the three-read strategy to understand the following exercise from a statistics textbook, and then proceed to complete the exercise. Suppose that in a study to determine if hormone therapy increases risk of venous thrombosis in menopausal women, each person in a sample of 589 women who had been diagnosed with venous thrombosis was classified according to hormone use. Each woman in a sample of 2,243 women who had not been diagnosed with venous thrombosis was also classified according to hormone use. Data from the study are given in the accompanying table. The women in each of the two samples were selected at random from patients at a large HMO in a certain U.S. state.   Current Hormone Use None EsterifiedEstrogen ConjugatedEquineEstrogen Venous Thrombosis 382 86 121 No VenousThrombosis 1,439 505 299 Is there convincing evidence that the proportions of those who would fall into each of the hormone use categories are not the same for women who have been diagnosed with…