The mean of the $10$ observations is $11$. If one new observation is included,their mean becomes $12$. The included new observation is ........

The following observations are arranged in ascending order:
$26, 29, 42, 53, x, x+2, 70, 75, 82, 93$
If the median is $65,$ find the value of $x$.

The median of the following observations arranged in ascending order is $53 :$ $41, 48, x+1, x+5, 62, 72$. Find $x$.

The class mark of the class $90-120$ is:

Three coins were tossed $30$ times simultaneously. Each time the number of heads occurring was noted down as follows:
$0, 1, 2, 2, 1, 2, 3, 1, 3, 0,$
$1, 3, 1, 1, 2, 2, 0, 1, 2, 1,$
$3, 0, 0, 1, 1, 2, 3, 2, 2, 0$
Prepare a frequency distribution table for the data given above.

Find the mean,the median,and the mode of the observations:
$48, 41, 36, 35, 41, 37, 39, 52, 41, 48$