The one-time fling! Have you ever purchased an article of clothing (dress, sport
ID: 2907144 • Letter: T
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 15% 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
Explanation / Answer
X ~ Binomial (n,p)
Where n = 7 , p = 0.15
Binomial probability distribution is
P(X) = nCx px (1-p)n-x
a)
P( X = 0) = 7C0 0.150 0.857
= 0.3206
b)
P( X >= 1) = 1 - P( X = 0)
= 1 - 0.3206
= 0.6794
c)
P( X <= 2) = P( X = 0) + P( X = 1) + P( X = 2)
= 7C0 0.150 0.857 + 7C1 0.151 0.856 + 7C2 0.152 0.856
= 0.9262