3.4 Questions 1. What is the difference in average grade between students who never and ever attended SI? I have data on my last class before the midterm about their grades and attendance at SI sessions. I know that among people who never attended SI their average grade was 84.20, but for those who attended at least once their average grade was 95.35. Here is the bootstrap distribution. 40 40 Left Tail Two-Tail Right Tail samples = 1000 mean =-11.116 std. error=4.150 30 30 20 20 10 0 -25 -20 ** -15 -10 -5 0 -11.116 A. Define the parameters of interest. B. Provide the observed statistic of interest. Give the notation and value. C. Provide the 95% confidence interval? D. Interpret the 95% confidence interval in context. E. Provide the 99% confidence interval? F. Interpret the 99% confidence interval in context. G. Which is wider, the 95% or 99% confidence interval? Why? H. Do you have evidence that people who attended at least one SI session had higher grades than those who didn't attend at least one SI session? 2. We have data on the size of statistics graduate schools (number of students enrolled in the graduate programs). For all 82 programs, the average enrollment is 53.537 (median=45.5) and the standard deviation is 36.89. We took a random sample of 20 programs and found that the average in this sample was 44.55 (median=40) with a standard deviation of 32.042. We then used this sample to generate a bootstrap distribution with a center of 44.794 and a standard deviation of 6.932. A. What is the shape, center and spread of the distribution of the enrollment in all programs? B. What is the shape, center and spread of the distribution of average enrollment in the sampling distribution?