91Ó°ÊÓ

Among freshmen at a certain university, scores on the Math SAT followed the normal curve, with an average of 550 and an SD of \(100 .\) Fill in the blanks; explain briefly. (a) A student who scored 400 on the Math SAT was at the centile of the score distribution. (b) To be at the 75 th percentile of the distribution, a student needed a score of about

Which of the following are true? false? Explain or give examples. \(\begin{array}{l}{\text { (a) The median and the average of any list are always close together. }} \\ {\text { (b) Half of a list is always below average. }} \\ {\text { (c) With a large, representative sample, the histogram is bound to follow }} \\ {\text { the normal curve quite closely. }}\end{array}\) \(\begin{array}{l}{\text { (d) If two lists of numbers have exactly the same average of } 50 \text { and the }} \\ {\text { same SD of } 10 \text { , then the percentage of entries between } 40 \text { and } 60 \text { must }} \\\ {\text { be exactly the same for both lists. }}\end{array}\)