The mean of the numbers 3, 7, x, 11 and 9 is 8. Find the value of x.
A8
B10CORRECT
C12
D6
GCEFurther MathematicsProbability and Statistics2022
AI
Toaster Teacher
Why the answer is B, and why the others tempt you.
Mean = sum/count, so 8 = (3 + 7 + x + 11 + 9)/5. This gives 40 = 30 + x, therefore x = 10. The other options are plausible errors from miscounting or misadding the known values.
Want this in Pidgin, Yoruba, Igbo or Hausa? Sign up free →
Practice more Further Mathematics questions
GCE Further Mathematics has thousands more questions like this — with Worked answers on every one.