If the mean of the following data is $20.2,$ find the value of $p:$
$\begin{array}{|c|c|c|c|c|c|} \hline x & 10 & 15 & 20 & 25 & 30 \\ \hline f & 6 & 8 & p & 10 & 6 \\ \hline \end{array}$

There are $50$ numbers. Each number is subtracted from $53$ and the mean of the numbers so obtained is found to be $-3.5$. The mean of the given numbers is: (in $.5$)

$30$ children were asked about the number of hours they watched $TV$ programmes last week. The results are recorded as under:

Number of hours	$0-5$	$5-10$	$10-15$	$15-20$
Frequency	$8$	$16$	$4$	$2$

Can we say that the number of children who watched $TV$ for $10$ or more hours a week is $22$? Justify your answer.

If the mean of $20$ observations is $27.2$,then $\Sigma f_{i} x_{i}$ is ............

The difference of the highest and the lowest values in the data is called the ............

The following table gives the frequencies of most commonly used letters $a, e, i, o, r, t, u$ from a page of a book:

Letters	$a$	$e$	$i$	$o$	$r$	$t$	$u$
Frequency	$75$	$125$	$80$	$70$	$80$	$95$	$75$

Represent the information above by a bar graph.