Question

Below is the given frequency distribution of words in an essay

Number of Words	Number of Candidates
600 – 800	8
800 – 1000	22
1000 – 1200	40
1200 – 1400	18
1400 - 1600	12

Find the mean number of words written.

Answer 1

(Number of words)	Class Mark	(Number of candidates)	fiXi
Class intervals	Xi	Frequency
		fi
600 – 800	700	8	5600
800 – 1000	900	22	19800
1000 – 1200	1100	40	44000
1200 – 1400	1300	18	23400
1400 – 1600	1500	12	18000
Total		∑fi=100	∑fiXi=110800

Mean=

`barX=(Sigmaf_ix_i)/(Sigmaf_i)=110800/100=1108`

∴ Mean number of words written in an essay is 1108.