Question

as part of a nutrition study, researchers started by weighing the adults participating in their experiment. adults weights (lbs) 110 110 110 110 110 110 110 138 138 138 138 138 193 193 193 193 193 193 193 193. x is the weight that a randomly chosen adult weighed. what is the expected value of x? write your answer as a decimal.

Explanation:

Step1: Calculate the total number of data - points

There are 7 + 5+ 9 = 21 data - points.

Step2: Calculate the sum of all data - points

The sum is \(110\times7 + 138\times5+193\times9=770 + 690+1737 = 3197\).

Step3: Calculate the expected value

The expected value \(E(X)=\frac{\text{Sum of all data - points}}{\text{Total number of data - points}}=\frac{3197}{21}\approx152.238\).

Answer:

152.238