Question

As part of a nutrition study, researchers started by weighing the adults participating in their experiment. Weight (lbs) Number of adults 107 3 137 5 148 3 155 6 198 3 X is the weight that a randomly chosen adult weighed. What is the expected value of X? Write your answer as a decimal.

Answer 1

Expected value = X•f(X) divided by number of participants

Then find X•f(X) = (3•107 + 5•137 + 3•148 +6•155 +3•198 )

. = 321 + 685 + 444 + 930 + 594

. = 2974

Now divide by 20, number of adults

Expected value = 2974/20 = 148