This booklet is part of a series of four pamphlets, each intended to stand alone, which provide problems in probability and statistics at the secondary school level. Twelve different real-life examples (written by professional statisticians and experienced teachers) have been collected in this booklet to illustrate the ideas of mean, variation, and standard deviation of sets of data; certain probability distributions such as the normal, the binomial, and the hypergeometric; the central limit theorem; hypothesis testing, particularly the chi-square test; contingency tables; transforming data for linearity; and the method of least squares for fitting curves to data. The booklet was designed for students having a background of intermediate algebra and elementary probability. For other booklets and teachers' guides in this series, see SE 016 799 through SE 016 805. (DT)