In government data, a household consists of all occupants of a dwelling unit. Choose an American household at random and count the number of people it contains. Here is the assignment of probabilities for the outcome:

Number of persons: 1 2 3 4 5 6 7+

Probability: 0.25 0.32 ??? ??? 0.07 0.03 0.01 The probability of finding 3 people in a household is the same as the probability of finding 4 people. These probabilities are marked ??? in the table of the distribution.

The probability that a household contains 3 people must be

(a) 0.68.

(b) 0.32.

(c) 0.16.

(d) 0.08.

(e) between 0 and 1, and we can say no more.