1 A study of academic dishonesty among college students used a two-stage sampling design. The first stage chose a sample of 30 college and universities. Then the study authors mailed questionnaires to a stratified sample of 200 seniors, 100 juniors, and 100 sophomores at each school. One of the schools chosen has 1127 freshmen, 989 sophomores, 943 juniors, and 895 seniors. You have alphabetical lists of the students in each class. Explain how you would assign labels for stratified sampling. Then use table B, starting at line 122, to select the first 5 students in the sample from each stratum. After selecting 5 students for a stratum, continue to select the students for the next stratum.
2. To gather data on 1200-acre pine forest in Louisiana, the U.S. Forest Services laid a grid of 1410 equally spaced circular plots over a map of the forest. A ground survey visited a sample of 10% of these plots. How would you label the plots? Choose the first 5 plots in an SRS of 141 plots. (If you use Table B, start at line 105)
3. A study of 12,000 abled-bodied male students at the University of Illinois found that their times for the miles run were approximately Normal with mean 7.11 minutes and standard deviation 0.74 minute. Choose a student at random from this group and call his time for the mile Y. What is the probability P(Y ≥ 8) = ? Write the event "the student could run a mile in less than 6 minutes"in terms of values of the random variable Y. What is the probability of this event?
4. A test of H0 : p = 0.5 against Ha : p > 0.5 has a test statistic z = 1.876.
Is this test significant at the 5% level (α = 0.05)? Explain why or why not and draw a graph.
Is it significant at the 1% level (α = 0.01)? Explain why or why not and draw a graph