## Elementary Statistics (12th Edition)

The mean can be counted by summing all the data and dividing it by the number of data: Obama: $\frac{275+452+...+250}{15}=653.867$, McCain: $\frac{50+75+...+400}{15}=458.533$. The median is the average of the 1 or 2 (here 1) middle data: Obama:(500)/1=500, McCain:(400)/1=400. The African American drivers appear to speed more because their mean is more. Obama's mean and median are higher and the fact that he got more contributions makes us think that he is the favorite.