Answer:
12.23%
Step-by-step explanation:
Using an Excel spreadsheet we can determine the internal rate of return by using the IRR function:
inputs
-7873
102
123
121
155 + 11900 = 12055
IRR = 12.23%
You can also use a financial calculator, or do it by hand. Doing by hand is simply too much work for something that can be solved in a few seconds.