Q:

Thirty percent of all customers who enter a department store will make a purchase. Suppose that 6 customers enter the store and that these customers make independent purchase decisions. a. Find the probability that exactly 5 customers make a purchase b. Find that probability that at least 3 customers make a purchase c. Find the probability that two or fewer customers make a purchase d. Find the probability that at least one customer makes a purchase. e. As the manager of the department store, how should store associates persuade customers who enter the store to make a purchase

Accepted Solution

A:
Answer:Step-by-step explanation:Let's use binomial distribution, because we are interested in find the total number of successes in a sequence of n independent experiments.In probability, a binomial distribution is used in a Bernoulli process. That is, a sequence of experiments of n independent  trials, each asking a dichotomous question, that means it only has two answers. One answer is a success (probability: p) and the other is a failure (probability: 1-p). In this case, every customer who enters in the store is the experiment. If they make a purchase is a success event, taking into account that every purchase decision has to be independent.[tex]P(X=x) = C(n,x)p^{x} (1-p)^{n-x}[/tex]x= total number of successn= total number of experimentsp=probability of success on an indivual trial[tex]C(n,x) = \frac{n!}{x!(n-x)!}[/tex]a) x= 5 ------> customers that make a purchasen= 6 ------> total customersp=0.3[tex]p(X=5)= C(6,5)(0.3)^{5} (1-0.3)^{6-5} \\p(X=5)=0.102[/tex]b) At least 3 customers make a purchase. x ≥ 3[tex]P(X\geq 3)=1-P (X=0)-P(X=1)-P(X=2)\\P(X\geq 3)=1-(C(6,0)(0.3^{0})(0.7)^{6}) - (C(6,1)(0.3^{1})(0.7)^{5}) - (C(6,2)(0.3^{2})(0.7)^{4})\\ P(X\geq 3) = 1-0.11765-0.30253-0.32414\\P(X\geq3)= 0.2557[/tex]c) At most 2 customers make a purchase. x ≤ 2 [tex]P(X\leq2) = P(X=0) + P(X=1) + P(X=2)\\P(X\leq2) = (C(6,0)(0.3^{0})(0.7)^{6}) + (C(6,1)(0.3^{1})(0.7)^{5}) + (C(6,2)(0.3^{2})(0.7)^{4})\\P(X\leq2) = 0.11765-0.30253-0.32414\\P(X\leq2)=0.7443[/tex]d)At least 1 customer makes a purchase. x ≥ 1[tex]P(X\geq 1)=1-P(X=0)\\P(X\geq 1)= 1-C(0,6)(0.3)^{0}(0.7)^{6} \\P(X\geq 1)= 1-0.11765 = 0.8824[/tex]e)They must be kind to customers, always willing to help and give information about products clearly and honestly.Have enough inventory and offer promotions for the purchase of more than one productHave an agile payment system that avoids rows and delays in purchases.