recent study by researchers at North Carolina State University found thousandsof errors in 12 of the

recent study by researchers at North Carolina State University found thousandsof errors in 12 of the most widely used high schoolscience texts. For example, the Statue of Liberty isleft-handed; volume is equal to length multipliedby depth (Time Magazine, February 12, 2001). Thebooks are so bad that Philip Sadler, director of sci-ence education at the Harvard-Smithsonian Centerfor Astrophysics, decided to conduct a study of their
effects. He recorded the physics marks of collegestudents who had used a textbook in high school andthe marks of students who did not have a high schooltextbook. Do these data allow us to infer that studentswithout high school textbooks in science outperformstudents who used textbooks