Question

The mean of four numbers is 2.6 one of the four numbers is 5 find out the mean of the other three numbers

Answer 1

Step-by-step explanation:

4 • 2.6 = 10.4 is the sum of the 4 numbers

(10.4 - 5)/3 = 5.4/3 = 1.8 is the mean of the other three numbers.

Answer 2

Given,

Mean $\[ = 2.6\]$

Total numbers $\[ = 4\]$

One number, d = 5

Solution,

Consider the numbers are $\[a,b,c,d\]$

Mean $\[ = \frac{{\sum n }}{n}\]$

$\[ \Rightarrow \frac{{\left( {a + b + c + d} \right)}}{4} = 2.6\]$

$\[ \Rightarrow \left( {a + b + c + 5} \right) = 4 \times 2.6\]$

$\[ \Rightarrow a + b + c = 5.4\]$

Calculate the mean of other three numbers,

$\[\begin{array}{l} = \frac{{a + b + c}}{3}\\ = \frac{{5.4}}{3}\\ = 1.8\end{array}\]$

Hence the mean of other three numbers is $\[1.8\]$