Most Australian youth-sports leagues separate athletes by birthdate, and the cutoff date is January 1st. Thus, those children born in January and February have some physical advantages in youth sports over those born in November and December. A study suggests that those physical advantages enjoyed early in life impact the likelihood of a child becoming a professional athlete. The table below gives the number of Australian-born 2009 Australian Football League players born in different months of the year, as well as the proportion of births expected if the birthdates of the athletes matched the distribution of all births nationally. Use this data to answer the questions on the following page.

months

TABLE 7.16 Birthdates nationally in Australia and for Australian football players Months Proportion Nationally Actual for AFL Players Jan-Mar 0.248 196 Apr-June 0.251 162 Jul-Sep 0.254 137 Oct-Dec 0.247 122