Question

The 20 numbers in list A have an average of 9.5. The 10 numbers in list B have an average of 8.3. If the two lists are combined to make a new list, what is the average of the 30 numbers in the new list?

Answer 1

9.1

Explanation:

If list A has an average of 9.5, then we can say that all of the terms are 9.5

If list B has an average of 8.3, then we can say that all of the terms are 8.3.

9.5*20 = 190

8.3*10 = 83

190+83 = 273. This is the sum of all of the terms in the 30-number list.

To find the average, we can divide 273 by 30, which equals 9.1.