The file S02_39.xlsx contains SAT test scores (two verbal components, a mathematical component, and the sum of these three) for each state and Washington DC in 2009. It also lists the percentage of high school graduates taking the test in each of the states.
a. Create a histogram for each of the numerical variables. Are these distributions essentially symmetric or are they skewed?
b. Compare the distributions of the average verbal scores and average mathematical scores. In what ways are these distributions similar? In what ways are they different?
c. Find the mean, median, and mode of the set of percentages taking the test.
d. For each of the numerical variables, which is the most appropriate measure of central tendency? Explain the reasoning behind your choice.
e. How does the mean of the combined variable relate to the means of the Critical Reading, Math, and Writing variables? Is the same true for medians?