If, for x > 0, the mean of 22.5, 56, 42.5, 2x +1, x–2, 3x, 36 is 30, then the value of x is ___________.

Correct option is C

Given:

Numbers 22.5, 56, 42.5, 2x+1, x−2, 3x, and 36

Mean =  30

Formula used:

Mean = $$\frac{Sum \ of \ all \ Number}{ Total \ number\ of\ numbers}$$

Solution:

The mean is given as 30.

The total number of numbers is 7.

​$$\frac{22.5+56+42.5+(2x+1)+(x−2)+3x+36}{7}$$ = 30

​$$\frac{156+6x}{7}$$ = 30

156 + 6x = 210

6x = 210 − 156

6x = 54

x = $$\frac{54}{6}$$

x = 9 

The value of x is 9

Thus, correct answer is (c) 9

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