Question

In a college biology class, only half of the class earned a passing grade. Out of all the students, 45% studied and passed. What is the probability of someone having studied, given that they passed?

Answer 1

Answer: Probability of someone having studied given that they passed is 0.9=0.9×100%=90%.

Explanation:

Since we have given that

Probability of the class earned a passing grade = 50%

Probability of the class studied and passed = 45%

We need to find the probability of someone having studied given that they passed.

So, we will use "Conditional probability ":

`P(Studied\mid passed)=(P(Studied \cap Passed))/(P(passed))\\\\P(Studied\mid passed)=(45)/(50)\\\\P(Studied\mid passed)=0.9`

Hence, Probability of someone having studied given that they passed is 0.9=0.9×100%=90%.

Answer 2

Something that will help you to know is the next formula:

P(having studies given that they passed) = P(studied and pass) / P(passed) = 0.45/ 0.5 = 0.9

With that in mind, now you can have the answer with this formula. Hope this helps