10.61 SAT versus ACT. The SAT and the ACT are the two major standardized tests that colleges use to evaluate candidates. Most students take just one of these tests. However, some students take both. Consider the scores of 60 students who did this. How can we relate the two tests?

  1. (a) Plot the data with SAT on the x axis and ACT on the y axis. Describe the overall pattern and any unusual observations.

  2. (b) Find the least-squares regression line and draw it on your plot. Give the results of the significance test for the slope.

  3. (c) What is the correlation between the two tests?