Sangeetha Pulapaka
1

It is given that n  = 60, let f_{1} = x and f_{2} = y

C. I                                  Frequency                                        Cumulative Frequency

0 - 10                                      5                                                          5

10-20                                      x                                                          x+5

20- 30                                    20                                                        x+25

30-40                                      15                                                        x+40

40-50                                      y                                                        x+y+40

50-60                                      5                                                        x+y+45

So, x+y+45 = 60  x+y = 15

The median is 28.5 which means it lies in the class interval 20 -30

So, the median class is 20 -30

Lower limit of median class is 20

C.F of the class preceeding the median class is x+5

Frequency (f) of the median class is 20

Class size (h) is 10

Median =     l + \frac{\Big(\frac{n}{2} - cf\Big)} {f}

Plugging in the values we get x = 8

Since x+y = 16 we get y = 7

Hence the missing frequencies are 8 and 7 respectively