The following is the distribution of weights (in kg) of 52 persons:
`{("Weight in kg","Person"),(30-40,10),(40-50,15),(50-60,17),(60-70,6),(70-80,4):}`
What is the lower limit of class 50-60?
Find the class marks of the classes 40-50, 50-60
What is the class size?

Explanation

(i) The lower limit of the class '50-60 is 50'.
(ii) Class mark for the class 40-50:
i.e `(40+50)/2=45`
Again class mark for `50-60 :(50+60)/2=55`
(iii)Here the class size is `40-30` i.e `10`