Find the mode of $14, 25, 14, 28, 18, 17, 18, 14, 23, 22, 14, 18.$

$5$ people were asked about the time in a week they spend doing social work in their community. They said $10, 7, 13, 20$ and $15$ hours,respectively. Find the mean (or average) time in a week devoted by them for social work.

The lengths of $40$ leaves of a plant are measured correct to one millimetre,and the obtained data is represented in the following table:

Length (in $mm$)	Number of leaves
$118-126$	$3$
$127-135$	$5$
$136-144$	$9$
$145-153$	$12$
$154-162$	$5$
$163-171$	$4$
$172-180$	$2$

$(i)$ Draw a histogram to represent the given data. [Hint: First make the class intervals continuous]
$(ii)$ Is there any other suitable graphical representation for the same data?
$(iii)$ Is it correct to conclude that the maximum number of leaves are $153 \, mm$ long? Why?

In a mathematics test given to $15$ students,the following marks (out of $100$) are recorded:
$41, 39, 48, 52, 46, 62, 54, 40, 96, 52, 98, 40, 42, 52, 60$
Find the mean,median,and mode of this data.

In a city,the weekly observations made in a study on the cost of living index are given in the following table:

Cost of living index	Number of weeks
$140-150$	$5$
$150-160$	$10$
$160-170$	$20$
$170-180$	$9$
$180-190$	$6$
$190-200$	$2$
Total	$52$

Draw a frequency polygon for the data above (without constructing a histogram).

Give one example of a situation in which $(i)$ the mean is an appropriate measure of central tendency.