Using conditional probability, it is found that there is a 0.1165 = 11.65% probability that a person with the flu is a person who received a flu shot.
Conditional Probability
In which
- P(B|A) is the probability of event B happening, given that A happened.
is the probability of both A and B happening.
- P(A) is the probability of A happening.
In this problem:
- Event A: Person has the flu.
- Event B: Person got the flu shot.
The percentages associated with getting the flu are:
- 20% of 30%(got the shot).
- 65% of 70%(did not get the shot).
Hence:

The probability of both having the flu and getting the shot is:

Hence, the conditional probability is:

0.1165 = 11.65% probability that a person with the flu is a person who received a flu shot.
To learn more about conditional probability, you can take a look at brainly.com/question/14398287
Let's first denote:
F - a favorable response
F' - an unfavorable response
S - successful
We know that:

So, from the conditional probability, we can calculate:

Answer E.
375/1000. You can then reduce that to get 3/8. So the answer is 3/8
(88 + 92 + 96 + x) / 4 = 90
(276 + x) / 4 = 90
276 + x = 90 * 4
276 + x = 360
x = 360 - 276
x = 84 <=== he would need an 84