Help for Insomniacs A recent study shows that just one session of cognitive behavioral therapy can help people with insomnia. In the study, forty people who had been diagnosed with insomnia were randomly divided into two groups of 20 each. People in one group received a one-hour cognitive behavioral therapy session while those in the other group received no treatment. Three months later, 14 of those in the therapy group reported sleep improvements while only 3 people in the other group reported improvements.

(a) What are the cases in this study?

(b) What are the relevant variables? Identify each as categorical or quantitative.

(c) If we create a dataset of the information with cases as rows and variables as columns, how many rows and how many columns would the dataset have?