CASE STUDY: JMP008
Siblings
by Dr. DeWayne Derryberry, Idaho State University, Department of Mathematics
Key Concepts: Histograms, normal quantile plots, log transformations, confidence intervals, inverse transformation

Objective
Use data from a survey of students to perform exploratory data analysis and to evaluate the performance of different approaches to a statistical analysis.
Background
The following data are a mixture of surveys from a small liberal arts school on the West Coast. Each semester students in introductory statistics courses complete a survey. One of the questions is the number of siblings in their immediate family. The results of the survey are similar each semester, but results have been combined in a haphazard manner so that there is no chance any particular class can be identified.
The Task
Estimate the average number of siblings for the general population.