For the following data,the modal class is .... .

Class	$0-10$	$10-20$	$20-30$	$30-40$	$40-50$
Frequency	$7$	$16$	$25$	$32$	$20$

The following is the cumulative frequency distribution (of less than type) of $1000$ persons each of age $20$ $years$ and above. Determine the mean age.

Age (years)	$30$	$40$	$50$	$60$	$70$	$80$
Cumulative Frequency	$100$	$220$	$350$	$750$	$950$	$1000$

Find the median of the following frequency distribution:

Class	$0-20$	$20-40$	$40-60$	$60-80$	$80-100$
Frequency	$5$	$15$	$20$	$18$	$2$

In a frequency distribution,the modal class is $70-85$ with frequency $25$. The frequencies of the classes succeeding and preceding the modal class are $20$ and $8$ respectively. Then,the values of $f_{0}, f_{1}$ and $f_{2}$ are respectively.

Find the mean,median and mode of the following frequency distribution:

Class	$30-40$	$40-50$	$50-60$	$60-70$	$70-80$	$80-90$	$90-100$
Frequency	$5$	$7$	$12$	$10$	$8$	$6$	$2$

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	$2$	$22$	$19$	$14$	$13$