Observations of a data are $28, 16, 9, 17, 82, 71, 41, 18, 25, 15$. Find the range of the data.

Find the median of the observations $18, 8, 12, 3, 20, 4, 10, 5$.

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

The class marks of a continuous distribution are: $1.04, 1.14, 1.24, 1.34, 1.44, 1.54$ and $1.64$. Is it correct to say that the last interval will be $1.55-1.73$? Justify your answer.

Mode of the data $15, 14, 19, 20, 14, 15, 16, 14, 15, 18, 14, 19, 15, 17, 15$ is

The mean of the data $\frac{4}{7}, \frac{4}{9}, \frac{3}{7}, \frac{5}{9}$ is ........