Question

The following is the distribution of weights (in kg) of 52 persons:

Weight in kg	Persons
30-40	10
40-50	15
50-60	17
60-70	6
70-80	4

(i) What is the lower limit of class 50-60?
(ii) Find the class marks of the classes 40-50, 50-60.
(iii) What is the class size?

Answer 1

(i) The lower limit of the class 50$-$60 is 50.
(ii) Class mark for the class 40$-$50:
$$\begin{gathered} \frac{40+50}{2} \\ =\frac{90}{2} \\ =45 \end{gathered}$$
Again, class mark for the class 50$-$60:
$$\begin{gathered} \frac{50+60}{2} \\ =\frac{110}{2} \\ =55 \end{gathered}$$
(iii) Here the class size is 40$-$30, i.e. 10.