The table below shows the size of American house-holds as reported by the U.S. Census Bureau. (U.S.Census Bureau, Current Population Survey.)

Size of household x                           No. of households (millions) f(x)

1………………………………………….….                         26.7

2……………………………………………...                       34.7

3……………………………………………...                       17.2

4……………………………………………...                       15.3

5……………………………………………...                        6.9

6……………………………………………...                        2.4

7(or more)*………………………..…...                        1.4

                                                                Total = 104.6

*To simplify your work, use 7 as the maximum house-hold size, even though the Census Bureau’s table reports the last entry as “7 or more.”

a. Compute the mean household size.

b. What is the median household size?

c. Compute the variance and the standard deviation for household size.