Question

if the mean of four numbers 3, 4, X, 6, and 5 then X is
a.) 5
b.) 6
c.) 7
d.) 8

Answer 1

Step-by-step explanation:

$\frac{3 + 4 + x + 6}{4} = 5 \\ 3 + 4 + x + 6 = 20 \\ 13 + x = 20 \\ x = 7$

Answer 2

Given,

If the mean of four numbers 3, 4, X, 6 is 5

To Find,

The value of X =?

Solution,

We can solve the question as follows:

It is given that the mean of four numbers is 5. We have to find the value of X.

$Mean\: of\: 3, 4, x, 6 = 5$

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

$Mean = \frac{Sum\: of\: all\: observations}{Total\: no.\: of\: observations}$

Here,

$Sum\: of\: all\: observations = 3 + 4 + X + 6 = 13 + X$

$Total\: no.\: of\: observations = 4$

$Mean = 5$

Substituting the values in the formula,

$5 = \frac{13 + X}{4}$

$5*4 = 13 + X$

$20 = 13 + X$

$X = 20 - 13 = 7$

Hence, the value of X is 7.