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 70cm , find the mean height if the girls in the class

Answer 1

Answer: 270 cm

Step-by-step explanation:

Total = 100 students  Boys = 60      Girls = 40

Mean height of 100 students = 150

Mean = Sum/Number

Sum of heights of 100 students = Mean * Number = 150*100 = 15000 cm

Mean height of 60 boys = 70 cm

Sum of heights of 60 boys = Mean * Number = 70*60 = 4200 cm

Sum of heights of 40 girls = 15000 - 4200 = 10,800 cm

Mean height of 40 girls = Sum/Number = 10800/40 = 270 cm