Question

Out of 100 numbers. Sixteen were 5's, twenty-one were 6's, thirty were 7's and the rest were 8's. Find the arithmetic mean of the numbers.

Answer 1

what is the answer? Explain.

Answer 2

First, find out how many 8's there are. You have 100 numbers. You know that 16+21+30 of them were NOT 8's. So deduct that sum from 100 to get how many are 8's.

Then you just need a mean, which in this case, is most easily computed as a weighted average. The sum of ALL the numbers is:

5(# of 5's) + 6(# of 6's) + 7(# of 7's) + 8(# of 8's)

So find that sum, then divide by 100. That's your mean.

Answer 3

[16*5+21*6+31*7+32*8]/100

Answer 4

no. of 8 numbers=100-(16+21+31)
=32.