In: Math
Twenty percent of the contestants in a scholarship competition come from Pylesville High School, 40% come from Millerville High School, and the remaining come from Lakeside High School. Two percent of the Pylesville students are among the scholarship winners; 3% of the Millerville contestants and 5% of the Lakeside contestants win. a) If a winner is chosen at random, what is the probability that they are from Lakeside? b) What percentage of the winners are from Pylesville?
P : Event of contestant come from Pylesville High School
P(P) = 20/100 =0.2
M : Event of contestant come from Millerville High School
P(M) = 0.40
L : Event of contestant come from Millerville High School
P(L) = 1-0.2-0.4 = 0.4
W : Event of chosen contestant is a winner
Given,
Two percent of the Pylesville students are among the scholarship winners : P(W|P) = 2/100 =0.02
3% of the Millerville contestants : P(W|M) = 3/100 =0.03
5% of the Lakeside contestants win:P(W|L) = 5/100 =0.05
a) If a winner is chosen at random, probability that they are from Lakeside = P(L|W)
By Bayes theorem,
If a winner is chosen at random, what is the probability that they are from Lakeside = P(L|W) =0.5556
b) percentage of the winners are from Pylesville = P(P|W)*100
Percentage of the winners are from Pylesville = P(P|W)*100 =0.1111*100 =11.11%