Scenario: Does the age at which babies learn to crawl depend on the time of the year that the babies were born? Data were collec
ted from parents who brought their babies into the University of Denver’s Infant Study Center to participate in one of a number of experiments between 1988 and 1991. Parents reported the birth month and the age in which their child first began to crawl. The resulting data were grouped by month of birth: January, May, and September.
