Question

The mean height of 26 pupils is 147 cm. One of these pupils is 173 cm and leaves the group. Determine the new mean height of the group. Give your answer correct to 1 decimal place.

Answer 1

The new mean height of the remaining 25 pupils, after a 173 cm tall pupil leaves the group of originally 26 pupils, is 146.0 cm when rounded to one decimal place.

Step-by-step explanation:

The mean height of 26 pupils is 147 cm. If one pupil who is 173 cm tall leaves the group, we can calculate the new mean height for the remaining 25 pupils.

First, we calculate the total height for the original 26 pupils by multiplying the mean height by the number of pupils: 147 cm x 26 = 3822 cm.

Then, subtract the height of the pupil who leaves: 3822 cm - 173 cm = 3649 cm.

Finally, divide this new total by the remaining number of pupils to find the new mean height: 3649 cm / 25 = 145.96 cm, which we can round to 146.0 cm when giving our answer correct to one decimal place.