Chapter 14.1, Problem 8E

The article “Psychiatric and Alcoholic Admissions Do Not Occur Disproportionately Close to Patients’ Birthdays” (Psychological Reports, 1992: 944–946) focuses on the existence of any relationship between the date of patient admission for treatment of alcoholism and the patient’s birthday. Assuming a 365-day year (i.e., excluding leap year), in the absence of any relation, a patient’s admission date is equally likely to be any one of the 365 possible days. The investigators established four different admission categories: (1) within 7 days of birthday; (2) between 8 and 30 days, inclusive, from the birthday; (3) between 31 and 90 days, inclusive, from the birthday; and (4) more than 90 days from the birthday. A sample of 200 patients gave observed frequencies of 11, 24, 69, and 96 for categories 1, 2, 3, and 4, respectively. State and test the relevant hypotheses using a significance level of .01.