The median number of students in each music class is 19 people find the missing value

16,?, 24, 17, 20, 21

Arrange the numbers from least to greatest

16 17? 20 21 24

Median is the number in the middle, since there is 6 numbers the the median is the missing value + 20.

To find the missing value multiply 19 x 2 = 38

Now subtract 38 - 20 = 18

The missing value is 18

The median is 18+20 = 38 ... 38/2 = 19