Last school year, the student body of a local university consisted of 30% freshmen, 24% sophomores, 26% juniors, and 20% seniors. A sample of 500 students taken from this year's student body showed the following number of students in each classification. Freshmen 125 Sophomores 103 Juniors 131 Seniors 141 ​ We are interested in determining whether or not there has been a significant change in the classifications between the last school year and this school year. The expected number of freshmen is a. 120

Suppose we want to compare the GPA for students in at least three different social classes (Upper, Middle, Working).  We obtain GPA records for a randomly selected set of 30 students, ten from each social class group.  What test should you use and why?

A group of 11 students was selected at random and asked for their high school GPA and their freshmen GPA in college the subsequent year. The results were: Student High School GPA Freshmen GPA 1 2.0 1.6 2 2.2 2.0 3 2.6 1.8 4 2.7 2.8 5 2.8 2.1 6 3.1 2.0 7 2.9 2.6 8 3.2 2.2 9 3.3 2.6 10 3.6 3.0 We would like to know whether there is a linear relationship between the high school GPA and the college freshmen GPA, and we would like to be able to predict the freshmen GPA, if we know that the high school GPA of another student is, say, 3.4.  Provide the two requested scatter plots for this data (put college freshman GPA on the Y (vertical) axis!).  a) What would be your approximate 95% prediction interval for question (g)? b) Show your scatterplot with the predicted trend line below

Superpowers A total of 415 children from the United Kingdom and the United States who completed a survey in a recent year were randomly selected. Each student's country of origin was recorded along with which superpower they would most like to have: the ability to fly, ability to freeze time, invisibility, superstrength, or telepathy (ability to read minds). The data are summarized in the following table. Country U.K. U.S. Fly 54 45 Freeze time 52 44 Invisibility 30 37 Superpower 20 23 Superstrength Telepathy 44 66 a. What proportion of students in the sample are from the United States? b. Find the distribution of superpower preference for the students in the sample using relative frequencies. c. What percent of students in the sample are from the United Kingdom and prefer telepathy as their superpower preference?