Considering the probabilities of getting each question right, his expected score for the test is 90.8.
Joe's expected score is given by the sum of the expected score for each question.
We have that:
Hence his expected score is given by:
E(X) = 12 x 6 + 9 x 1/5 x 6 + 4 x 1/3 x 6 = 90.8.
More can be learned about the expected score of a distribution at https://brainly.com/question/13617733
#SPJ1
