Answer:
A) 2
B) 0.239
Step-by-step explanation:
Part A) Expected value of a binomial distribution is the number of trials times the probability of success.
X = np
Given X = 1 and p = 0.65:
1 = 0.65n
n = 1.54
Rounding up, a salesperson should expect 2 customers until he finds a customer that makes a purchase.
Part B) Use binomial probability.
P = nCr pʳ qⁿ⁻ʳ
where n is the number of trials,
r is the number of successes,
p is the probability of success,
and q is the probability of failure (1−p).
Given n = 3, r = 1, p = 0.65, q = 0.35.
P = ₃C₁ 0.65¹ 0.35³⁻¹
P ≈ 0.239
Or, using binompdf function in a calculator:
binompdf(n, p, r)
= binompdf(3, 0.65, 1)
≈ 0.239
