Question

Deleting in a university, 30% of the students doing a course in statistics use the book authored by a1 45% use the one authored by a2 and 25% use the one authored by a3. the proportion of students who learnt about each of these books through their teachers are: a1= 0.50, a2=0.30 and a3=0.20. one of the students selected at random revealed that he learnt about the book he is using through his teachers. find the probability that the book used is authored by a2

Answer 1

Answer:

27/67  = 0.4

Step-by-step explanation:

30% of the students doing a course in statistics use the book authored by a1

the proportion of students who learnt about each of these books through their teachers are: a1= 0.50

(0.45 * 0.3) /(0.3 * 0.5  +  0.45*0.3  + 0.25 * 0.2)

= (0.135)/(0.15 + 0.135 + 0.05)

= 0.135/0.335

= 135/335

= 27/67