Question

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

Number of Words	Number of Candidates
$600-800$	$14$
$800-1000$	$22$
$1000-1200$	$30$
$1200-1400$	$18$
$1400-1600$	$16$

Find the mean number of words written

Answer 1

Number of Words	Class Mark $\left(x_i\right)$	No. of Candidates $\left(f_i\right)$	$f_i{x}_i$
$600-800$	$700$	$14$	$9,800$
$800-1000$	$900$	$22$	$19,800$
$1000-1200$	$1100$	$30$	$33,000$
$1200-1400$	$1300$	$18$	$23,400$
$1400-1600$$	$1500$	$16$	$23,400$
		$\sum f_i=100$	$\sum f_i{x}_i=110,000$

Mean $\left(\overline{X}\right)=\frac{\sum f_i{x}_i}{\sum f_i}=\frac{1,10,000}{100}=1,100$
$\therefore$ Mean number of words in an essay is $1100$.