Answer: Probability that students who did not attend the class on Fridays given that they passed the course is 0.043.
Step-by-step explanation:
Since we have given that
Probability that students attend class on Fridays = 70% = 0.7
Probability that who went to class on Fridays would pass the course = 95% = 0.95
Probability that who did not go to class on Fridays would passed the course = 10% = 0.10
Let A be the event students passed the course.
Let E be the event that students attend the class on Fridays.
Let F be the event that students who did not attend the class on Fridays.
Here, P(E) = 0.70 and P(F) = 1-0.70 = 0.30
P(A|E) = 0.95, P(A|F) = 0.10
We need to find the probability that they did not attend on Fridays.
We would use "Bayes theorem":
![P(F\mid A)=\dfrac{P(F).P(A\mid F)}{P(E).P(A\mid E)+P(F).P(A\mid F)}\\\\P(F\mid A)=\dfrac{0.30\times 0.10}{0.70\times 0.95+0.30\times 0.10}\\\\P(F\mid A)=\dfrac{0.03}{0.695}=0.043](https://tex.z-dn.net/?f=P%28F%5Cmid%20A%29%3D%5Cdfrac%7BP%28F%29.P%28A%5Cmid%20F%29%7D%7BP%28E%29.P%28A%5Cmid%20E%29%2BP%28F%29.P%28A%5Cmid%20F%29%7D%5C%5C%5C%5CP%28F%5Cmid%20A%29%3D%5Cdfrac%7B0.30%5Ctimes%200.10%7D%7B0.70%5Ctimes%200.95%2B0.30%5Ctimes%200.10%7D%5C%5C%5C%5CP%28F%5Cmid%20A%29%3D%5Cdfrac%7B0.03%7D%7B0.695%7D%3D0.043)
Hence, probability that students who did not attend the class on Fridays given that they passed the course is 0.043.