Please HELP with Compound Monthly Growth Rate

[Lady Tzyion]

I am so confused, in all of the video tutorials and research I have completed, I cannot understand how these professionals reached their answers. I am trying to complete the financials for my start-up biz plan, currently working on profits and losses. I do not want to use excel. I need to comprehend this by hand, first. I have to figure out the CMGR for projected sales and sales costs, over 12 mos. Annually, Semi-Annually, and Quarterly. I cannot seem to find a more simplified explanation of these examples, below. When I try to do them on my own, I am not coming up with the same results.

Regarding these 2 equations :

CMGR = 5,000/100 1/[12 – 1] – 1
= 42.71%

CMGR = 248/100 1/[6 - 1] -1 = 0.2 OR 20%

in my research, if I find the (A) 5th root of 248 and then the (B) 5th root of 100, I then divide B from A, subtract 1 from that answer, leading to the results they have presented, above. I do not remember how to find it, correctly.

I found ->
3 x 3 x 3 x 3 x 3 = 243

&

2.5 x 2.5 x 2.5 x 2.5 x 2.5 = 97.66.

Now, I am stuck and after research upon research. I began to gain traction on my Cash flow statement, this is slowing me down. I feel special, I did well in algebra but have not had to use these ways of calculating in over 2 decades. I need this explained in the most simplified terms, please?

 

[Prof]

I am not sure what your question is about. I can explain the first equation that you wrote. You have not submitted all the sales information, but I will assume that you start with 100 and you have 5000 in the 12th month. The time period n-1 is 11 months. CMGR = (last month/first month)^(1/(n-1)- 1= (5000/100)^(1/11)-1 = .4271 = 42.71% That is where the answer comes from. The second computation is done the same way assuming that you have 248 in the 6th month.