05 Problem 4 7 Points Professor Walker is a sleep researcher at the University of California. Berkeley, and teaches an undergraduate course in the psychology department that describes the evolutionary importance of sleep. During the rst class of the semester, he asks a random sample of students to record how many hours of sleep they obtain each night. Then. during the last class of the semester. he asks the same group of students the same question that is. how many hours of sleep they obtain each night. Average Hours of Standard deviation (3) in sleep per night the hours of sleep per night First Class 6.8 2.1 Last Class 3 4 7-5 1.5 Difference = (Last First) Professor Walker thinks that the number of hours slept each night may change throughout the semester as students learn more about the implications of sleep. Is the average difference in the hours of sleep per night for each student at the end of the semester minus at the beginning of the semester different from 0? Use a significance level of 5%. Make sure to show all relevant steps for the hypothesis test. Obesity is defined as a BMI of 30.0 or above. The CDC estimates that 37.9% of Americans are considered obese. How large a sample would be required to construct a 95% confidence interval estimate of the proportion of Americans that are obese within 2.5 percentage points (meaning #2.5 percentage points)? On= 1537 On = 1446 On= 1020 On = 1447