Question

Find out range and coefficient range.

Marks	10−20	20−30	30−40	40−50	50−60
No. of students	12	18	14	63	19

Answer 1

Marks	No. of Students
10 − 20	12
20 − 30	18
30 − 40	14
40 − 50	63
50 − 60	19

$$\begin{gathered} \mathrm{Range}=Upper\mathrm{Limit}\mathrm{of}\mathrm{the}\mathrm{Highest}\mathrm{Class}\mathrm{Interval}-\mathrm{Lower}\mathrm{Limit}\mathrm{of}\mathrm{the}\mathrm{Lowest}\mathrm{Class}\mathrm{Interval} \\ \mathrm{or},\mathrm{Range}=60-10=50 \end{gathered}$$

$\mathrm{Coefficient}\mathrm{of}\mathrm{Range}=\frac{H-L}{H+L}=\frac{60-10}{60+10}=\frac{50}{70}=0.715$

Hence, the range is 50 marks and coefficient of range is 0.715