Question

CONDITIONAL PROBABILITY URGENT?

Answer 1

WE need to find the probability ($\frac{Junior}{Boy}$

We know $P(\frac{A}{B})= \frac{P(A and B)}{P(B)}$

P($\frac{Junior}{Boy}$)=$\frac{P(Junior and Boy)}{(Boy)}$

First we find P(Boy)

From the table we can see that we have 12 boys out of (12+18=30) students

So P(Boy) = $\frac{12}{30}$

Now we find the intersection of Junior and Boy

WE look at the Junior row and boys column that is 2

{P(Junior ∩ Boy) = $\frac{2}{30}$

P($\frac{Junior}{Boy}$)=$\frac{P(Junior and Boy)}{(Boy)}$

P($\frac{Junior}{Boy}$)= $\frac{\frac{2}{30}}{\frac{12}{30}}$

= $\frac{2}{12}$ = $\frac{1}{6}$

P($\frac{Junior}{Boy}$) = $\frac{1}{6}$