Enteroliths Are Calcifications That Form in the Gut of a Horse

Multiple Choice

Enteroliths are calcifications that form in the gut of a horse. The stones can cause considerable morbidity and mortality. A study was conducted to investigate the factors (such as diet and environment) that may be related to the formation of enteroliths. The study contained 62 horses with enteroliths (cases) and 75 horses without (controls) . The graph below contains side-by-side boxplots of the ages for cases and controls. Based on the boxplots, the mean age for the cases:

A) is lower than the mean age for the controls.
B) is approximately the same as the mean age for the controls.
C) is higher than the mean age for the controls.
D) cannot be determined from boxplots.