Question

The table below shows the number of students in class 10 of a school, classified according to their heights:

Height (cm)		Number of Students
120 − 125 125 − 130 130 − 135 135 − 140 140 − 145 145 − 150 150 − 155 155 − 160		19 36 23 23 43 21 23 12

Calculate the mean height

Answer 1

We can make the complete table as follows:

Height (cm)		Number of Student		Class Average		Total Height
120 − 125		19		122.5		2327.5
125 − 130		36		127.5		4590.0
130 − 135		23		132.5		3047.5
135 − 140		23		137.5		3162.5
140 − 145		43		142.5		6127.5
145 − 150		21		147.5		3097.5
150 − 155		23		152.5		3507.5
155 − 160		12		157.5		1890.0
Total		200				27750

Mean height =