Question

Wegmans food stores conducted a study to see how many customers will return to the same store in the future. The study showed that 40% of the customers visiting a specific store will return in the future to the same store. Suppose seven customers are selected at random, what is the probability that:

(a) Exactly four customers will return?

(b) All seven customers will return?

(c) At least six customers will return?

(d) At least one customer will return?

(e) How many customers would be expected to return to the same store?

Answer 1

X : number of customers will return to the same store in the future.

X ~ bin (n,p)

where, n = 7

p = 40% =0.4

q = (1-p) = (1-0.4) = 0.6

the pmf of the distribution be:-

a). the probability that Exactly four customers will return is :-

b). the probability that All seven customers will return is:-

c). the probability that At least six customers will return is :-

d).the probability that At least one customer will return is :-

e).the number of customers would be expected to return to the same store is:-

[ as we know that expectation is binomial distribution is n*p ]

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