SW A local youth service agency has begun a sex education program for teenage girls who have been referred by the juvenile courts. The girls were given a 20-item test for general knowledge about sex, contraception, and anatomy and physiology upon admission to the program and again after completing the program. The scores of the fi rst 15 girls to complete the program are listed below.

Case Pretest Posttest A 8 12 B 7 13 C 10 12 D 15 19 E 10 8 F 10 17 G 3 12 H 10 11 I57 J 15 12 K 13 20 L4 5 M 10 15 N 8 11 O 12 20 Construct frequency distributions for the pretest and posttest scores. Include a column for percentages. (HINT: There were 20 items on the test, so the maximum range for these scores is 20. If you use 10 class intervals to display these scores, the interval size will be 2. Since there are no scores of 0 or 1 for either test, you may state the fi rst interval as 2–3. To make comparisons easier, both frequency distributions should have the same intervals.)