Question

Compute the mode from the following data:

Class interval	1 – 5	6 – 10	11 – 15	16 – 20	21 – 25	26 – 30	31 – 35	36 – 40	41 – 45	46 – 50
Frequency	3	8	13	18	28	20	13	8	6	4

Answer 1

Clearly, we have to find the mode of the data. The given data is an inclusive series. So, we will convert it to an exclusive form as given below:

As the class 20.5 – 25.5 has the maximum frequency, it is the modal class. 

Now, x_k = 20.5, h = 5, f_k = 28, f_k-1 = 18, f_k+1 = 20

= (20.5 + 2.78)

= 23.28 

Hence, mode = 23.28