Question

If the mean of three observations x+2, x+4 and x+6 is 15, then x is equal to__

12
13
15
11

Answer 1

(x + 2) + (x + 4) + (x + 6) = 15

3x + 12 = 15

3x = 15 - 12

3x = 3

x = 1

Answer 2

Answer:

Mean= sum of all observations/total number of observations

thus

15=x+2+x+4+x+6/3

15=3x+12/3

15=x+12

15-12=x

x=3