Four female shoppers are to be randomly selected at a mall t

Four female shoppers are to be randomly selected at a mall tomorrow. Each one will be asked: “Did you come to this mall last week?”. The response given by each of shopper will be recorded.

a) List all the outcomes of the sample space.

b) Let E be the event that at least two of the selected shoppers will say to the question. Find P(E)

Solution

Outcomes 1 YYYY 2 YYYN 3 YYNY 4 YNYY 5 NYYY 6 YYNN 7 YNNY 8 NNYY 9 YNYN 10 NYNY 11 NYYN 12 YNNN 13 NYNN 14 NNYN 15 NNNY 16 NNNN Number of customers who said yes 0 1 2 3 4 Probability 0.0625 0.25 0.375 0.25 0.0625