Question

class mark of a particular class is 10.5 and class size is 7 then find the class interval

Answer 1

Let Lower limit be l and Upper Limit be u

We are given , l+u = 21
                and,-l+u = 7

By adding above Eqns

   2u = 28 so, u = 14

   so, l = 7
Hence class interval is 7-14

Answer 2

Answer:

(7,14)

Step-by-step explanation:

Class size h = 7

Class mark = a = 10.5

Lower limit of class = $a-\frac{h}{2}$

Lower limit of class = $10.5-\frac{7}{2}$

Lower limit of class = $7$

Upper limit of class = $a+\frac{h}{2}$

Upper limit of class = $10.5+frac{7}{2}$

Upper limit of class = $14$

Hence the class interval is (7,14)