Question

If one of the subjects is randomly selected find the probability that the person is over 40 years of age given that they drink root beer.

Answer 1

The probability of the event to occur is:

`P(E)=\frac{\#\text{ of outcomes at which the event occurs}}{To\text{tal number of outcomes}}`

The number of outcomes at which the person is over 40 years of age and drink root beer is: 30

The total number of outcomes is: 40+35+20+25+20+30+20+30+25=255

The probability is then:

`\begin{gathered} P(E)=(30)/(255) \\ \text{Simplify dividing by 15 the numerator and the denominator:} \\ P(E)=(30/15)/(255/15)=(2)/(17) \end{gathered}`