Question

Derrick needs to figure out how he’s doing on his test scores so far this year. You can help by calculating the mean and the median to get an overall picture of his scores. Below are all of his scores:

25, 40, 68, 85, 95, 98, 70, 78, 85, 100

Answer 1

Mean = 74.4

Median = 81.5

Explanation:

25, 40, 68, 85, 95, 98, 70, 78, 85, 100

Mean = Sum of values / Number of values

Number of values = 10

= 25 + 40 + 68 + 70 + 78 + 85 + 85 + 95 + 98 + 100/10

= 744/10

= 74.4

Median

Rearranging the given data

= 25, 40 ,68 ,70 ,78 ,85 ,85 , 95 ,98 ,100

Formula for median = 1/2(n + 1)th value

n = 10

Hence

1/2(10 + 1)th value

1/2(11)th value

= 5.5 th value

This fall between the 5th and 6th value

5th value = 78

6th value = 85

Hence: 78 + 85/2

= 163 / 2

= 81.5