Find the missing frequencies in the following frequency distribution whose mean is $34$.

$x$	$10$	$20$	$30$	$40$	$50$	$60$	Total
$f$	$4$	$f_1$	$8$	$f_2$	$3$	$4$	$35$

 

Find the missing frequencies in the following frequency distribution whose mean is $50$.

Find the greatest value of $p$, when the mean of the following distribution is $20$.

The mean of the following distribution is $50$.

Find the value of $a$ and hence the frequencies of $30$ and $70$