Question

9. The mean
of 10, 6, 13, x + 3, 2 and 2x – 1 is 9. The value of x is​

Answer 1

10, 6, 13, x + 3, 2 ,2x – 1

mean = sum of all observations

total number of observations

sum of observations = 10 + 6 + 13 + x + 3 + 2 + 2x – 1

= 33 + 3x

total observations = 6

mean = 9

9 = 33 + 3x

6

33 + 3x = 9 × 6

33 + 3x = 54

3x = 54 - 33

3x = 21

x = 21/3

x = 7