Question

N is a set of numbers whose average (arithmetic mean) is 3. M is a set that is generated by doubling each number in N. What is the average of the numbers in set M?

1/3

2

3

6

9

Answer 1

If you double the individual values the average result will double.

Answer 2

Let \[x\] be the sum of numbers in N, then the sum of numbers in M is \[2x\]
The number of numbers in N and M are the same, so if \[n\] represents the numbers in N and M, then the average of M is \[\frac{ 2x }{ n }=2\times \frac{ x }{ n }=2\times3=6\]

Answer 3

If you consider the fact that you're just doubling the numerator...you'll see that you're doubling the average as well.

Answer 4

so is it 6?

Answer 5

Yes...