The heights (in $cm$) of $9$ students of a class are as follows:
$155, 160, 145, 149, 150, 147, 152, 144, 148$
Find the median of this data. (in $\text{ cm}$)

Consider the marks,out of $100$,obtained by $51$ students of a class in a test,given in the table below. Draw a frequency polygon corresponding to this frequency distribution table.

Marks	Number of students
$0-10$	$5$
$10-20$	$10$
$20-30$	$4$
$30-40$	$6$
$40-50$	$7$
$50-60$	$3$
$60-70$	$2$
$70-80$	$2$
$80-90$	$3$
$90-100$	$9$
Total	$51$

Find the mean of the marks obtained by $30$ students of Class $IX$ of a school.
$\begin{array}{llllllllll}10 & 20 & 36 & 92 & 95 & 40 & 50 & 56 & 60 & 70 \\ 92 & 88 & 80 & 70 & 72 & 70 & 36 & 40 & 36 & 40 \\ 92 & 40 & 50 & 50 & 56 & 60 & 70 & 60 & 60 & 88\end{array}$

The relative humidity (in $\%$) of a certain city for a month of $30$ days was as follows:

$98.1$	$98.6$	$99.2$	$90.3$	$86.5$	$95.3$	$92.9$	$96.3$	$94.2$	$95.1$
$89.2$	$92.3$	$97.1$	$93.5$	$92.7$	$95.1$	$97.2$	$93.3$	$95.2$	$97.3$
$96.2$	$92.1$	$84.9$	$90.2$	$95.7$	$98.3$	$97.3$	$96.1$	$92.1$	$89$

$(i)$ Construct a grouped frequency distribution table with classes $84-86, 86-88$,etc.
$(ii)$ Which month or season do you think this data is about?
$(iii)$ What is the range of this data?

The following observations have been arranged in ascending order. If the median of the data is $63$,find the value of $x.$
$29, 32, 48, 50, x, x+ 2, 72, 78, 84, 95$

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?