I need to calculate the rate of return for investments part 2.?

I posted a question this morning in regard to finding the weighted average of an investment to see how I average out. I just found out that they are all allocated at different percentages. Could you please review the following and give me some guidance?

Investments are as follows.
A. 10% allocation, 4.7% ROR
B. 10% allocation, negative 19% ROR
C. 10% allocation, 94.7% ROR
D. 10% allocation, 39.6% ROR
E. 20% allocation, 4% ROR
F. 20% allocation, 15.3% ROR
G. 20% allocation, 60% ROR

I stink at math and things like this just tend to confuse me, but I want to be able to track investment performance myself so that I can monitor it. Thank you in advance.

Try this: Say your total investment dollars are $100. So for investiment A, you would invest $10. 4.7% of $10 is 47 cents. Then for b, you invest $10, and you lose $1.90 because $1.90 is 19% of $10. Do this for all of your investments. Then, take all your gains and losses, add them together, and divide by 100. This will give you your weighted average rate of return. Good luck!

Are those beginning of period allocations or end of period allocations? It makes a difference. Did you make any contributions or withdrawals during the period? That will make a difference, too.