Answer 1

Class-interval:	10 - 15	15 - 20	20 - 25	25 - 30	30 - 35	35 - 40
Frequency:	30	45	75	35	25	15

Here the maximum frequency is 75 then the corresponding class 20 – 25 is the model class

L = 20, h = 25 – 20 = 5, f = 75, f1 = 45, f2 = 35

Mode `=L+(f-f_1)/(2f-f_1-f_2)xxh`

`=20+(75-45)/(2xx75-45-35)xx5`

`=20+(30xx5)/70`

`=20+150/70`

= 20 + 2.14

= 22.14