STEP - BY - STEP EXPLANATION
What to find?
The mean.
Given:
11, 12, 15, 16, 17, 22, 24, 29, 33, 38
Step 1
Check if it arrange in ascending or descending order.
Step 2
Pick the middle number.
If it is one, then the number is the median, however of their are two middle number than you add and divide by 2.
From the given data above, the middle numbers are 17 and 22
ANSWER
19.5