SOLUTION: In a set of seven numbers, the average of the first four is 15 and the average of the last three is 8. what is the average of all seven numbers

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Question 1067688: In a set of seven numbers, the average of the first four is 15
and the average of the last three is 8. what is the average of
all seven numbers
Found 2 solutions by ikleyn, Edwin McCravy:
Answer by ikleyn(52800) About Me  (Show Source):
You can put this solution on YOUR website!
.
%284%2A15+%2B+3%2A8%29%2F7.

Calculate and think why it is so.



Answer by Edwin McCravy(20059) About Me  (Show Source):
You can put this solution on YOUR website!
Instead of doing your homework for you, I'll do one 
exactly like it with different numbers.
You can use it as a step-by-step guide:

The exactly similar problem is:

In a set of eleven numbers, the average of the first six is 9 and
the average of the last five is 20. what is the average of all
eleven numbers?
in a set of eleven numbers,
Let the numbers be a, b, c, d, e, f, g, h, i, j, k

the average of the first 6 is 9 
So

%28a%2Bb%2Bc%2Bd%2Be%2Bf%29%2F6=9

and therefore

a+b+c+d+e+f = 54

and the average of the last 5 is 20. 
%28g%2Bh%2Bi%2Bj%2Bk%29%2F5=20

and therefore

g+h+i+j+k = 100

what is the average of all eleven numbers


Answer = 14

Now you do yours exactly step-by-step the same way.

Edwin