Question

The following numerically ordered sequence of numbers has a mean of 17 and a median of 18.

7, a, 12, 15, 17, b, 20, 22, 24, 25
Given this information, the values of a and b must be:

Answer 1

A then b you do b first to solve

Answer 2

a = 9

b = 19

Explanation:

DO B FIRST

The mean is the average of all the terms (numbers) in the sequence

To find the average you find the sum of the terms and divided the sum by the number of terms there are.

The mean times the number of terms equals the sum of all the terms subtract the terms that you know from the sum to get A

a = 17(10)-7-12-15-17-19-20-22-24-25

a = 170-161

a = 9

The median is found by taking the average of the two middle terms

Our middle terms are 17 and B

the median times 2 equals the sum of the two terms and then subtract the term you know from the sum

b = 18(2)-17

b = 36-17

b = 19