For some given data,if $Z + M = 108$ and $Z - M = -6$,then the mean $\bar{x} = \ldots \ldots \ldots$

For the calculation of mode of the following frequency distribution,$f_{0} = \dots \dots \dots \dots \dots$

Class	$1-3$	$3-5$	$5-7$	$7-9$	$9-11$
Frequency	$6$	$3$	$8$	$2$	$1$

The median class in the following frequency distribution is $\ldots \ldots \ldots \ldots .$

Class	$10-25$	$25-40$	$40-55$	$55-70$	$70-85$	$85-100$
Frequency	$5$	$21$	$21$	$8$	$25$	$20$

In the formula $Z = l + \left( \frac{f_{1} - f_{0}}{2f_{1} - f_{0} - f_{2}} \right) \times c$ for the mode,$f_{1} = \ldots \ldots \ldots$

Find the mode of the following frequency distribution:

Class	$20-30$	$30-40$	$40-50$	$50-60$	$60-70$	$70-80$	$80-90$
Frequency	$8$	$12$	$27$	$43$	$55$	$37$	$18$

In the formula $Z = l + \left( \frac{f_{1} - f_{0}}{2f_{1} - f_{0} - f_{2}} \right) \times c$ for the mode,$f_{0} = \ldots \ldots \ldots$