AOT limited is considering two mutually exclusive projects - cable and satellite.  The possible NPVs for every project and their associated probabilities are as follows:

Cable:                                                  Satellite:

NPV ($'000)   Probability                   NPV ($'000)   Probability

10                    10%                             15                    60%

20                    50%                             20                    20%                

25                    40%                             40                    20%

Determine the standard deviation for every project.  Which project has the higher level of risk?