Question

what is the mean age of 7 students in a class if 3 are 12 years old, 2 are 10 years old, and 2 are 9 years old?
o 3
o 10.6
o 24.6
o 74

Explanation:

Step1: Calculate total age

$3\times12 + 2\times10+2\times9=36 + 20+18 = 74$

Step2: Calculate mean age

$\frac{74}{7}\approx10.6$

Answer:

10.6