Question

Below is the given frequency distribution of words in an essay:

Number of words	Number of Candidates
600  -  800	12
800  -  1000	14
1000 - 1200	40
1200 - 1400	15
1400 - 1600	19

Find the mean number of words written.

Answer 1

No. of words	Class Mark	No. of candidate	fx
	x	f	fx
600 - 800	700	12	8400
800 - 1000	900	14	12600
1000 - 1200	1100	40	44000
1200 - 1400	1300	15	19500
1400 - 1600	1500	19	28500
		∑f =100	∑fx = 113000

Mean by Direct method
Mean `(bar("x")) = (∑"f""x")/(∑"f") =113000/100`
                 =   1130  words