Question

The one-time fling! Have you ever purchased an article of clothing (dress, sports jacket, etc.), worn the item once to a party, and then returned the purchase? This is called a one-time fling. About 5% of all adults deliberately do a one-time fling and feel no guilt about it! In a group of seven adult friends, what is the probability of the following? (Round your answers to three decimal places.)

(a) no one has done a one-time fling


(b) at least one person has done a one-time fling


(c) no more than two people have done a one-time fling

Answer 1

Let X denotes the number of adults deliberately do a one-time fling in a randomly selected group of seven adult friends.

Here,

X ~ Binomial(n = 7, p = 0.05)

The probability mass function of X is

Now,

a) The probability that no one has done a one-time fling

b) The probability that at least one person has done a one-time fling

c) The probability that no more than two people have done a one-time fling