For a symmetrical distribution,if ${Q_1} = 25$ and ${Q_3} = 45$,the median is

The median of $21$ observations is $40$. If each observation greater than the median is increased by $6$,what will be the new median of the observations?

The mean weight per student in a group of seven students is $55 \ kg$. If the individual weights of $6$ students are $52, 58, 55, 53, 56$ and $54 \ kg$,then the weight of the seventh student is.....$kg$.

The median of a set of $19$ observations is $30$. If two observations with values $8$ and $32$ are added,what is the median of the new set of $21$ observations?

The mean of a set of $n$ numbers,when each is divided by $5$,is $\frac{X}{5}$. What is the mean of the original $n$ numbers?

If the arithmetic mean of the numbers $x_1, x_2, x_3, ..., x_n$ is $\bar{x}$,then the arithmetic mean of the numbers $ax_1 + b, ax_2 + b, ax_3 + b, ..., ax_n + b$,where $a$ and $b$ are two constants,would be: