Question

A researcher is interested in the actions of football fans at tailgate parties. He believes there is some relationship between what they do and their level of education. He does a survey of a group of tailgaters and finds that 19% had less than a high school degree, 60% had a high school diploma, and 21% had a college degree or higher.  

What is the probability that you would select at random a tailgater with a college degree from the group?

What is the probability that you would select at random a tailgater with a college degree or one with less than a high school diploma?

What is the probability that you would select at random 3 tailgaters total - 2 with a college degree and 1 with a high school diploma?

Answer 1

Let's write the event for the information.

A = tailgater with a less than a high school degree

B =  tailgater with a high school diploma

C =  tailgater with a college degree or higher.  

Therefore P( A ) = 0.19; P( B ) = 0.60 ; P( C ) = 0.21

What is the probability that you would select at random a tailgater with a college degree from the group?

That is P( a tailgater with a college degree from the group ) = P( C ) = 0.21

P( a tailgater with a college degree or one with less than a high school diploma ) =

P( B) + P( C) = 0.21 + 0.60 = 0.81

What is the probability that you would select at random 3 tailgaters total - 2 with a college degree and 1 with a high school diploma?

P(  at random 3 tailgaters total - 2 with a college degree and 1 with a high school diploma) = P(B)*P(C)*P(C) + P(C)*P(B)*P(C)+P(C)*P(C)*P(B) = 3*0.60*0.21*0.21 = 0.07938