The following distribution gives the daily income of $50$ workers of a factory.

Daily income (in Rs.)	$100-120$	$120-140$	$140-160$	$160-180$	$180-200$
Number of workers	$12$	$14$	$8$	$6$	$10$

Convert the distribution above to a less than type cumulative frequency distribution,and draw its ogive.

Thirty women were examined in a hospital by a doctor and the number of heartbeats per minute were recorded and summarized as follows. Find the mean heartbeats per minute for these women,choosing a suitable method.

Number of heartbeats per minute	$65$-$68$	$68$-$71$	$71$-$74$	$74$-$77$	$77$-$80$	$80$-$83$	$83$-$86$
Number of women	$2$	$4$	$3$	$8$	$7$	$4$	$2$

$A$ life insurance agent found the following data for the distribution of ages of $100$ policy holders. Calculate the median age,if policies are given only to persons having age $18$ years onwards but less than $60$ years.

Age (in years)	Number of policy holders
Below $20$	$2$
Below $25$	$6$
Below $30$	$24$
Below $35$	$45$
Below $40$	$78$
Below $45$	$89$
Below $50$	$92$
Below $55$	$98$
Below $60$	$100$

Consider the following distribution of daily wages of $50$ workers of a factory.
$\begin{array}{|l|c|c|c|c|c|} \hline \text{Daily wages (in Rs.)} & 100-120 & 120-140 & 140-160 & 160-180 & 180-200 \\ \hline \text{Number of workers} & 12 & 14 & 8 & 6 & 10 \\ \hline \end{array}$
Find the mean daily wages of the workers of the factory by using an appropriate method.

$A$ student noted the number of cars passing through a spot on a road for $100$ periods each of $3\, \text{minutes}$ and summarized it in the table given below. Find the mode of the data:

Number of cars	$0-10$	$10-20$	$20-30$	$30-40$	$40-50$	$50-60$	$60-70$	$70-80$
Frequency	$7$	$14$	$13$	$12$	$20$	$11$	$15$	$8$

The following table gives the production yield per hectare of wheat of $100$ farms of a village.

Production yield (in kg/ha)	Number of farms
$50-55$	$2$
$55-60$	$8$
$60-65$	$12$
$65-70$	$24$
$70-75$	$38$
$75-80$	$16$

Change the distribution to a 'more than type' distribution,and draw its ogive.