Question

The daily consumption of milk in litres by 10 families in a colony are given below:

3.5, 3, 2, 2.5, 4, 3, 1, 5, 3.5, 1.5

Find their mean and median.

Answer 1

Sum of all the observations = 3.5 + 3 + 2 + 2.5 + 4 + 3 + 1 + 5 + 3.5 + 1.5 = 29

Number of families = 10

Mean = `"Sum of observations"/"Total number of families"`

= `29/10`

= 2.9

The mean daily consumption is 2.9 litres.

Arranging the numbers in ascending order = 1, 1.5, 2, 2.5, 3, 3, 3.5, 3.5, 4, 5

n = 10 observations

∴ Two middle numbers

`(n/2)`th

= `10/2`

= 5th

`(n/2 + 1)`th

= `10/2 + 1`

= 6th 

Median = `(3 + 3)/2`

= 3

The median daily consumption is 3 litres.