calculate monthly average percentage of change

[Guest]

Not sure how to do this, If I have a range of numbers, (50, 55, 75, 100)
Percentage of increase is (10%, 36%, 33%)
Average monthly increase is 26%

How do I get excel to calculate the above?

 

[CarlosAntenna]

If you have your data in column A

50
55
75
100

In b2 enter =a2/a1-1
fill down the column
In b5 enter =average(b2:b5)
format column B as percentage

-- Carlos

 

[JE McGimpsey]

Assuming you data is in A1:A4, one way:

B2: =A2/A1-1 ====> 10%
B3: =A3/A2-1 ====> 36.36%
B4: =A4/A3-1 ====> 33.33%

If by "average monthly increase" you mean the average of the individual
monthly increases, that's just

=AVERAGE(B2:B4) ===> 26.57%

OTOH, if by "average monthly increase" you mean the constant monthly
increase that, when applied to 50, yields 100 after 3 months, then use

=(A4/A1)^(1/3) - 1 ==> 25.99%