Question

*What should be the value of x so that the average of the numbers 2,x,3,5,7 is 4 ?*

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Answer 1

$\frac{(2 + x + 3 + 5 + 7)}{5} = 4 \\ (2 + x + 3 + 5 + 7) = 4 \times 5 \\ (17 + x) = 20 \\ x = 20 - 17 \\ x = 3$

Answer 2

See we will use formula of mean
= 2+x+3+5+7/5= 4
17+x/5=4
17+x=20 cross multiply
X=20-17
X= 3