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

$Z - M = \ldots \ldots \ldots \times (M - \bar{x})$

Find the mean of the distribution:

Class	$1-3$	$3-5$	$5-7$	$7-10$
Frequency	$9$	$22$	$27$	$17$

For some given data,if $M = 62.5$ and $\bar{x} = 64$,then $Z = \ldots$

In the formula $\bar{x} = \frac{\Sigma f_{i} x_{i}}{\Sigma f_{i}}$,$\Sigma f_{i}$ represents ........

If $x_{i}$ are the midpoints of the class intervals of grouped data,$f_{i}$ are the corresponding frequencies,and $\bar{x}$ is the mean,then $\sum (f_{i} x_{i} - f_{i} \bar{x})$ is equal to