Question

Find the mean and the median of: 10,12, 12, 15, 15, 17, 18, 18, 18 and 19

Answer 1

Given data: 10,12, 12, 15, 15, 17, 18, 18, 18 and 19

Here, number of terms = 10 which is even

∴ Median =`1/2 {"n"/2 "th term" + ("n"/2 + 1)"th term"}`

`= 1/2 {10/2 "th term" + (10/2 + 1) "th term"}`

`= 1/2 {5 "th term" + 6 "th term"}`

`= 1/2 {15 + 17}`

`= 1/2 xx 32 = 16`

∴ Median = 16

Mean = `"Sum of observations"/"Number of observations"`

`= (10 + 12 + 12 + 15 + 15 + 17 + 18 + 18 + 18 + 19)/10`

`= 154/10 = 15.4`