For a given frequency distribution,$A = 450, c = 100, \Sigma f_{i} u_{i} = -20$ and $\Sigma f_{i} = 20$. Then,the mean $\bar{x} = \ldots$

In the formula $M = l + \frac{(\frac{n}{2} - cf)}{f} \times h$ for the median,$h = \ldots \ldots \ldots$

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?

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	$4$	$6$	$8$	$12$	$10$	$5$	$5$

Construction of a cumulative frequency table is useful in determining the

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