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 $\text{ cm}$)

$A$ study was conducted to find out the concentration of sulphur dioxide in the air in parts per million $(ppm)$ of a certain city. The data obtained for $30$ days is as follows:
$\begin{array}{llllll}0.03 & 0.08 & 0.08 & 0.09 & 0.04 & 0.17 \\ 0.16 & 0.05 & 0.02 & 0.06 & 0.18 & 0.20 \\ 0.11 & 0.08 & 0.12 & 0.13 & 0.22 & 0.07 \\ 0.08 & 0.01 & 0.10 & 0.06 & 0.09 & 0.18 \\ 0.11 & 0.07 & 0.05 & 0.07 & 0.01 & 0.04\end{array}$
$(i)$ Make a grouped frequency distribution table for this data with class intervals as $0.00 - 0.04, 0.04 - 0.08$,and so on.
$(ii)$ For how many days was the concentration of sulphur dioxide more than $0.11$ parts per million?

Three coins were tossed $30$ times simultaneously. Each time the number of heads occurring was noted down as follows:
$\begin{array}{llllllllll}0 & 1 & 2 & 2 & 1 & 2 & 3 & 1 & 3 & 0 \\ 1 & 3 & 1 & 1 & 2 & 2 & 0 & 1 & 2 & 1 \\ 3 & 0 & 0 & 1 & 1 & 2 & 3 & 2 & 2 & 0\end{array}$
Prepare a frequency distribution table for the data given above.

The following table gives the life times of $400$ neon lamps:

The time (in hours)	Number of lamps
$300-400$	$14$
$400-500$	$56$
$500-600$	$60$
$600-700$	$86$
$700-800$	$74$
$800-900$	$62$
$900-1000$	$48$

$(i)$ Represent the given information with the help of a histogram.
$(ii)$ How many lamps have a life time of more than $700$ hours?

Consider a small unit of a factory where there are $5$ employees: a supervisor and four labourers. The labourers draw a salary of $Rs. 5,000$ per month each,while the supervisor gets $Rs. 15,000$ per month. Calculate the mean,median,and mode of the salaries of this unit of the factory.

Give five examples of data that you can collect from your day-to-day life.