Question

Class mark of a particular class is 6.5 and class size is 3, then class interval is :

• A. 5 - 8
• B. 6.5 - 9.5
• C. 3.5 - 6.5
• D. 4.25

Answer 1

The correct option is A 5 - 8

Class mark is the mid point of the class interval.

Class size is the upper limit minus lower limit.

Given that class mark of a class is $6.5$ and

the class size is $3$

By option verification,

Opition A class mark is $\frac{5+8}{2}=\frac{13}{2}=6.5$ and

Class size is $8-5=3$ true

Option B class size is $9.5-6.5=4$ False

Option C class size is $6.5-3.5=3$ and

Class mark is $\frac{3.5+6.5}{2}=\frac{10}{2}=5$ false

Option D $4.25$ is not a class interval.

Therefore the class interval is $5-8$