20. Size of American households In government data, a household consists of all occupants of a dwelling unit, while a family consists of two or more persons who live together and are related by blood or marriage. So all families form households, but some households are not families. Here are the distributions of household size and family size in the United States: Number of Persons 2 3 5 6 7 Household probability 0.25 0.32 0.17 0.15 0.07 0.03 0.01 Family probability 0 0.42 0.23 0.21 0.09 0.03 0.02 Let X = the number of people in a randomly selected U.S. household and Y = the number of people in a randomly chosen U.S. family. (a) Make histograms suitable for comparing the probability distributions of X and Y. Describe any differences that you observe. (b) Find the mean for each random variable. Explain why this difference makes sense. (c) Find and interpret the standard deviations of both X and Y