If the mean of $3, 4, x, 7, 10$ is $6$,then the value of $x$ is

The mean of the series $a, a + nd, a + 2nd$ is

If for some $x \in R$,the frequency distribution of the marks obtained by $20$ students in a test is:
Marks: $2, 3, 5, 7$
Frequency: $(x+1)^2, 2x-5, x^2-3x, x$
Then the mean of the marks is:

Let $x_1, x_2, \ldots, x_{11}$ be $11$ distinct positive integers. If we replace the largest of these integers by the median of the other $10$ integers,then:

Let $M$ denote the median of the following frequency distribution. Then $20M$ is equal to:

Class	$0-4$	$4-8$	$8-12$	$12-16$	$16-20$
Frequency	$3$	$9$	$10$	$8$	$6$

The geometric mean of the numbers $4, 5, 10, 20, 25$ is .........