Question

There are 100 students in a class. The mean height of the class is 150 cm. If the mean height of 60 boys is 170cm, find the mean heigth if the girls in the class.

Answer 1

mean height= sum of all observation/number of observation
let the height of the girls be x
150=60+170+x/100
15000-230=x
x= 14770