Question

Assume Netflix’s current recommendation algorithm is imperfect. For a user who likes Stranger Things (after watching it), it predicted the user would like Stranger Things with probability 70%. For a user who did not like Stranger Things (after watching it), it predicted the user would like Stranger Things with probability 10%. Of all existing users on Netflix who watch Stranger Things, 30% like it. What is the algorithm’s predicted probability that a new user will like Stranger Things, with no other information known about the user?

a. 0.21 b. 0.28 c. 0.24 d. 0.27

Answer 1

Answer:

(B) 0.28

Explanation:

= Probability that a user will like stranger things given the user likes stranger things = 0.7

= Probability that a user will like stranger things given the user dislikes stranger things = 0.1

   = Probability of users that like stranger things = 0.3

= Probability of users that do not like stranger things = 0.7

Probability that a new user will like stranger things = * + *

= 0.7 *0.3 + 0.1*0.7

= 0.21 + 0.07

= 0.28