According to the U.S. Bureau of the Census, in 2013 in the United States the median family income was

$72,624 for white families, $41,505 for black families, and

$42,269 for Hispanic families.

(a) Identify the response variable and the explanatory variable for this analysis.

(b) Is enough information given to find the median when all the data are combined from the three groups?Why or why not?

(c) If the reported values were means, what else would you need to know to find the overall mean?