The formulas for EV is different between each source. For example, in Rita for

1. atypical EAC I could see AC + (BAC - EV) whereas in the below link AC + BAC - EV

2, Current variances are typical to future plus modified by performance

         Rita - AC + (BAC - EV) / (CPI^c + SPI^c) whereas in the below link it is EAC = AC + (BAC – EV) / (CPIc

x SPIc 

Please throw some light on this. I am confused. I dont want to choose a wrong answer just because wrong application of formula.