Chapter 3.3, Problem 141E

In each of Exercises 3.140–3.143, the quantitative data set under consideration has roughly a bell-shaped distribution. For each exercise,

1. a. construct a graph similar to Fig. 3.8 on page 118.
2. b. apply Property 1 of the empirical rule to make pertinent statements about the observations in the sample.
3. c. repeat part (b) for Property 2 of the empirical rule.
4. d. repeat part (b) for Property 3 of the empirical rule.

Model your solutions after those in Example 3.18 on page 121.

3.141 Student-to-Faculty Ratio. A sample of fifth-grade classes was studied in the journal article “Predicting Feelings of School Safety for Lower, Middle, and Upper School Students” (Applied Psychology in Criminal Justice, Vol. 7, Issue 2, pp. 59–76) by R. Bachman et al. One of the variables collected was the class size in terms of student-to-faculty ratio. The student-to-faculty ratios of the 81 fifth-grade classes sampled have a mean of 15.83 and a standard deviation of 1.74.