Question

4. A student has these scores on their assignments. The teacher is considering dropping a

lowest score. What effect does eliminating the lowest value, 0, from the data set have
on the mean and median? (Clue: Find the mean and the median with the zero and
with out the zero)
0, 40, 60, 70, 75, 80, 85, 95, 95, 100

Answer 1

Mean increases by 7.78

Median increases by 2.5

Explanation:

We first need to calculate the mean as follows

Mean = summation of the total values/Total number of elements

Mean = 700/10

= 70

if the teacher drops 0 then the new mean will be composed of 9 elements

New mean = 700/9

= 77.78

thus we see that dropping the lowest value increases the mean by 7.78

to find the median we need to get the middle value of the data. since it is arranged in ascending order we just have to pick the value. since the data is even we have two middle values,5th and 6th values.

(75+80)/2 = 77.5

if we drop the lowest value we remain with 9 elements. thus the median becomes the 5th value.

median = 80

thus the median Also increases by 80-77.5 = 2.5