Question

Regan counted the number of problems on each of her tests. Number of problems Number of tests 21 2 42 2 52 3 57 1 82 2 X is the number of problems that a randomly chosen test had. What is the expected value Write your answer as a decimal.

Answer 1

x y x*y

21 2 42

42 2 84

52 3 156

57 1 57

82 2 164

Sum 10 Sum 503

Division = 503/10

= 50.3

Result: The expected value is 50.3