.......... is not a measure of central tendency.

In a frequency distribution with total frequency $48$,$\bar{x}=70$,$\Sigma f_{i}=43+f$,and $A=66$. Then,the missing frequency $f=$ .........

The formula to find the median of a grouped data is $\ldots \ldots \ldots \ldots .$

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

Class	$0-10$	$10-20$	$20-30$	$30-40$	$40-50$	$50-60$	$60-70$
Frequency	$4$	$6$	$8$	$12$	$10$	$5$	$5$

Find the median of the following frequency distribution:

Class	$60-70$	$70-80$	$80-90$	$90-100$	$100-110$	$110-120$
Frequency	$5$	$15$	$20$	$30$	$20$	$8$

In the following distribution:

Monthly income range (in $Rs.$)	Number of families
Income more than $10000$	$100$
Income more than $13000$	$85$
Income more than $16000$	$69$
Income more than $19000$	$50$
Income more than $22000$	$33$
Income more than $25000$	$15$

The number of families having an income range (in $Rs.$) of $16000-19000$ is: