suppose you are reading a study conducted in the year 2000 about adolescent girls with anorexia nervosa in the united states. the authors report the following frequency data on regions where the 522 adolescent girls with anorexia nervosa in their random sample reside: observed frequencies region west south midwest northeast 110 206 110 96 you wonder whether the differences in the frequencies are due to the disease being more prevalent in certain areas of the country, whether the study simply included more girls from certain regions, or whether the distribution matches the geographic distribution of the us p