Consider the list of numbers...

Question

1. Consider the list of numbers:

12,13,14,15,15,16,16,17,20, __

Enter a number in the gap which will make the mean of all those number equal to 20.

Answer 1

The Mean is just the average of all the items that you have given to you.

To find the missing term I will just call "x"

And to find this mean (average) you just have to add up all the terms given and add term "x" as the unknown that you are trying to find.

Since the mean formula is mean = (terms added up)/(number of terms)

Set mean = 20 thus to find term "x" solve for "x" in the mean equation.

20= (12+13+14+15+15+16+16+17+20+x)/(10)

where 10 is the number of terms including "x"

So the missing term x= 200-(12+13+14+15+15+16+16+17+20) = 62