Question

In a recent survey in a Statistics class, it was determined that only 74% of the students attend class on Fridays. From past data it was noted that 88% of those who went to class on Fridays pass the course, while only 20% of those who did not go to class on Fridays passed the course.

a.What percentage of students is expected to pass the course?
b.Given that a person passes the course, what is the probability that he/she attended classes on Fridays?

Answer 1

a) 83%

b) 0.892

Explanation:

percentage that attends class on friday = 74%

percentage that pass because they attend class on friday = 88%

percentage that pass but did not go to school on friday = 20%

a) percentage of students expected to pass the course

= (74% x 88%) +(88% x 20%)

= 0.6512 + 0.176

= 0.8272

= 83%

b) If a person passes the course, what is the probability that he/she attended classes on Fridays

= 74% divided by 83%

= 0.892