A company is considering investing some independent proposals, The proposals with their expected net present values and standard deviations are given in the following table.

                                                                                                                        A             B             C           

Expected Net Present Value (in millions)                                                                $4.5      $2.4       $3.2

Standard Deviation (in millions)                                                                           1.4          0.9          1.2

The projects have the following correlations:

a)      Calculate the Expected Net Present Values of all the combinations, A+B, A+C, B+C, A+B+C

b)      Calculate the co-variance between A and B, A and C, B and C.

c)       Calculate the Standard Deviations of all the combinations, A+B, A+C, B+C, A+B+C

d)      Calculate the probability of negative Net Present Value of all the combinations, A+B, A+C, B+C, A+B+C