Calculate the last flow (in the mid of the 4th year) of the investment which for the first three years brings a positive flow of 2,600 PLN at the end of each year, than one flow (to calculate) in the mid of the following year. The investment amount is 7,000 PLN and the net present value of this investment is 618,69 PLN Use a discount rate of 8%. Please also calculate the profitability index for this investment. Comment the results and the entire investment (in the light of calculated above measures)