Four individuals with high levels of cholesterol went on a special crash diet, avoiding high-cholesterol foods ...

     Four individuals   with high levels of cholesterol went on a special crash diet,   avoiding high-cholesterol foods and   taking special supplements. Their total   cholesterol levels before and after the   diet were as follows:   Participant Before After   J. K. 287 255   L. M. M 305 269   A. K. 243 245   R. O. S. 309 247   Using the .05 level of significance, was   there a significant change in cholesterol   level? (a) Use the steps of hypothesis   testing. (b) Sketch the distributions   involved. (c) Explain your answer to   someone who has never taken a course in   statistics.