Question

Find the range and the coefficient of the range of the following data:

Marks 20 - 30, 30 - 40, 40 - 50, 50 - 60, 60 - 70, 70 - 80, 80 - 90

No. of Students = 10, 12, 15, 20, 25, 13, 38

• A. 70, 0.54
• B. 60, 1.54
• C. 70, 0.64
• D. 60, 0.64

Answer 1

Answer:

C. 70, 0.64

Solution:

Given:

Marks 20 - 30, 30 - 40, 40 - 50, 50 - 60, 60 - 70, 70 - 80, 80 - 90

No. of Students = 10, 12, 15, 20, 25, 13, 38

Formula Used:

Range = Upper limit of highest class interval - Lower limit of lowest class interval

Coefficient of range =$\frac{Range}{(H+L)}$

Where, H = Upper limit of highest class interval

And L = Lower limit of lowest class interval

Calculation:

⇒ Range = Upper limit of highest class interval - Lower limit of lowest class interval

⇒ Range = 90 - 20 = 70

Coefficient of range = $\frac{Range}{(H+L)}$

Coefficient of range = $\frac{70}{90+20}$

⇒ $\frac{70}{110}$ = 0.6363... ≈ 0.64

⇒ Coefficient of range = 0.64