Question

Mr. Oliver, a track coach, recorded the number of runners on all the nearby track teams. Number of members Number of teams 48 4 66 82 4 101 2 104 4 107 3 is the number of members that a randomly chosen team has. What is the expected value of X? Write your answer as a decimal.

Answer 1

The basic expected value formula is the probability of an event multiplied by the number of times the event happens: (P(x) * n).

To get the expected value, we will have to obtain the probability of getting each number of member

probability = number of expected event/ number of total outcome

Total outcome = 4 + 3 + 4 + 2 + 4 +3 = 20

pr(48) = 4/20 = 1/5 = 0.2

pr(66) = 3/20 = 0.15

pr(82)= 4/20 = 0.2

pr(101)=2/20 = 0.1

pr(104)=4/20 = 0.2

pr(107)=3/20 = 0.15

expected value of X = 48 x 0.2 + 66 x 0.15 + 82 x 0.2 + 101 x 0.1 + 104 x 0.2 + 107 x 0.15

=>82.85

Expected value of X = 82.85