Construct the cumulative frequency distribution of the following distribution:

Class	$12.5-17.5$	$17.5-22.5$	$22.5-27.5$	$27.5-32.5$	$32.5-37.5$
Frequency	$2$	$22$	$19$	$14$	$13$

Find the mean of the following frequency distribution:

Class	$10-20$	$20-30$	$30-40$	$40-50$	$50-60$	$60-70$
Frequency	$2$	$10$	$40$	$25$	$13$	$10$

(in $.7$)

For a given frequency distribution,$\Sigma f_{i} x_{i} = 1790$ and $\Sigma f_{i} = 50$. Then,the mean $\bar{x} = $ ..........

The following table shows the cumulative frequency distribution of marks of $800$ students in an examination:

Marks	Number of students
Below $10$	$10$
Below $20$	$50$
Below $30$	$130$
Below $40$	$270$
Below $50$	$440$
Below $60$	$570$
Below $70$	$670$
Below $80$	$740$
Below $90$	$780$
Below $100$	$800$

Construct a frequency distribution table for the data above.

Rachana had an average score of $45$ from $6$ tests. Her teacher dropped her lowest score,which is $30$,and calculated the average of the remaining scores to decide her grade. Which of the following gives her new average score?

For some given data,if $M + \bar{x} = 32$ and $M - \bar{x} = 2$,then $Z = \ldots \ldots \ldots$