# How Changing a Value Affects the Mean and Median

In this lesson we are given a data set. We find itâ€™s mean and median. Then one of its data is changed. We then find the changed mean and changed median after one of the data has been changed.

Find new mean and new median of the data set if a data is changed.

12, 15, 18, 13, 6, 14; 13 is changed to 5

### Solution

**Step 1:**

Mean = $\frac{(12 + 15 + 18 + 13 + 6 + 14)}{6}$ = 13; Median = 13.5

**Step 2:**

With data change

New Mean = $\frac{(12 + 15 + 18 + 5 + 6 + 14)}{6}$ = 11.67; New Median = 13

Find new mean and new median of the data set if a data is changed.

18, 15, 11, 3, 8, 4, 13, 12, 3; 15 is changed to 18

### Solution

**Step 1:**

Mean = $\frac{(18 + 15 + 11 + 3 + 8 + 4 + 13 + 12 +3)}{9}$ = 9.67; Median = 11

**Step 2:**

With data change

New Mean = $\frac{(18 + 18 + 11 + 3 + 8 + 4 + 13 + 12 +3)}{9}$ = 10 ; New Median = 11