question_answer

    Calculate the arithmetic mean of the following frequency distribution using the step deviation method.

Class interval	0-50	50-100	100-150	150-200	200-250	250-300
Frequency	17	35	43	40	21	24

     

Answer:

    Here,  Let the assumed mean be  

Class interval	Frequency	Mid-value
0-50 50-100 100-150 150-200 200-250 250-300	17 35 43 40 21 24	25 75 125=A 175 225 275	-2 -1 0 1 2 3	-34 -35 0 40 42 72

(2) Thus, we have and(1) Using step deviation method Mean,                                                                                                       (1)