Question

List a has 10 values, with average 82.2 and standard deviation 15.0. list b has 8 values, with average 106 and standard deviation 20.0. (a) suppose that the two lists are combined to produce a new list of 18 values. what is the average (mean) of this new list?

Answer 1

The average (mean) of the new list will be 92.777...

Explanation

List A has 10 values with average as 82.2 and list B has 8 values with average as 106.

So, the sum of 10 values in list A will be:  $82.2*10= 822$

and the sum of 8 values in list B will be:  $106*8= 848$

If the two lists are combined, then the sum of all 18 values in the new list $=822+848= 1670$

So, the average (mean) of this new list will be:  $\frac{1670}{18}=92.777...$