Question

4) If the average 18
,15,x,22,28and 31is 21 then value
of x is ?​

Answer 1

Answer:

12

Step-by-step explanation:

List of terms- 18, 15,x,22,28,31

Number of terms- 6

Average value- 21

Calculation of average:

(18+15+22+28+31+x)/6=21

x+114=126

x=126-114

x=12

Answer 2

Given,

The average of 18,15,x,22,28 and 31 is 21.

To Find,

The value of x =?

Solution,

We can solve the question as follows:

It is given that the average of 18,15,x,22,28, and 31 is 21. We have to find the value of x.

$The\: average\: of\: 8,15,x,22,28,31 = 21$

The average of a given set of observations is given as the sum of all the observations divided by the total number of observations.

The mean of a given set of observations is equal to the sum of all observations divided by the total number of observations.

$Average = \frac{Sum\: of\: all\: observations}{Total\: number\: of\: observations}$

Here,

$Sum\: of\: all\: observations = 18+15+x+22+28+31= 114 + x$

$Number\: of\: observations = 6$

Substituting the values in the above formula,

$21 = \frac{114+x}{6}$

Solving the above equation to find the value of x,

$21*6 = 114 + x$

$126 = 114 + x$

$x = 126 - 114$

$x = 12$

Hence, the value of x is equal to 12.