Question

(a)The class interval having highest frequency is-
(b)The class-mark of class 50-60 is-
(c)The size of each class intervals is-

Answer 1

$Class-Interval$	$Frequency$
$0-10$	$6$
$10-20$	$2$
$20-30$	$13$
$30-40$	$17$
$40-50$	$11$
$50-60$	$4$
$60-70$	$8$
$70-80$	$7$

$\left(i\right)$ The class interval having highest frequency $=30-40$

$\left(ii\right)$ The class mark of class $50-60$ $=\frac{50+60}{2}=\frac{110}{2}=55$

$\left(iii\right)$ The size of each class interval $=10-0=10$