Question

The heights (in cm) of 8 girls of a class are 140, 142, 135, 133, 137, 150, 148 and 138 respectively. Find the mean height of these girls and their median height.

Answer 1

Arranging in ascending order: 133, 135, 137, 138, 140, 142, 148, 150

Here, the number of girls = 8 which is even

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

= `1/2{8/2"th term"+(8/2+1)"th term"}`

= `12` {4th term + 5th term}

= `1/2` {138 + 140} cm

= `1/2xx278`

= 139 cm

∴ Mean =`(133+135+137+138+140+142+148+150)/8`

= `1123/8`cm

= 140.375 cm