For the set $A = \{x_1, x_2, x_3, x_4, x_5\}$,the variance is $4$ and the mean is $2$. For the set $B = \{y_1, y_2, y_3, y_4, y_5\}$,the variance is $5$ and the mean is $4$. Then,the variance of $A \cup B$ is

The mean of $5$ observations is $4.4$ and their variance is $8.24$. If three observations are $1, 2$ and $6$,the other two observations are

$\bar{x}$ and $\bar{y}$ are the arithmetic means of the runs of two batsmen $A$ and $B$ in $10$ innings respectively,and $\sigma_{A}$ and $\sigma_{B}$ are the standard deviations of their runs. If batsman $A$ is more consistent than $B$,then he is also a higher run scorer only when

The mean and variance of $7$ observations are $8$ and $16$ respectively. If five of the observations are $2, 4, 10, 12, 14$,find the remaining two observations.

If the coefficients of variation of two distributions are $40$ and $20$ and their variances are $144$ and $64$ respectively,then the mean of their arithmetic means is

The frequency distribution of daily working expenditure of families in a locality is as follows:

Expenditure in $Rs. (x)$	$0-50$	$50-100$	$100-150$	$150-200$	$200-250$
No. of families $(f)$	$24$	$33$	$37$	$b$	$25$

If the mode of the distribution is $Rs. 140$,then the value of $b$ is: