For a given frequency distribution,$A=325, c=50, \Sigma f_{i} u_{i}=28$ and $\Sigma f_{i}=200$. Then,mean $\bar{x}=\ldots \ldots \ldots . .$

In the formula $\bar{x} = A + \frac{\Sigma f_{i} u_{i}}{\Sigma f_{i}} \times c$,$u_{i} =$ .........

The formula to find the mean of an ungrouped data is ........

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

Find the mean of the following frequency distribution:

Class	$21-25$	$26-30$	$31-35$	$36-40$	$41-45$	$46-50$	$51-55$
Frequency	$18$	$32$	$30$	$40$	$25$	$15$	$40$

(in $.675$)

The mileage $(km/l)$ of $50$ cars of the same model was tested by a manufacturer and details are tabulated as given below:

Mileage $(km/l)$	$10-12$	$12-14$	$14-16$	$16-18$
Number of cars	$7$	$12$	$18$	$13$

Find the mean mileage.
The manufacturer claimed that the mileage of the model was $16 \, km/l$. Do you agree with this claim?