I have multiple probability values there are only two possible values in each category and only one per observation. See example table below. I need a formula to find what the overall probability would be given all the probabilities. I can do an average probability by adding and divided by 3 but I'm thinking there is a combination formula to do this. I'm would prefer to do this in Excel but I also have SPSS. Thanks!

Values Probability OBS Gender Race GPA Gender Race GPA Overall Probability of Graduating Student1 M W 3.6 .41 .55 .46 ? Student2 F A 3.5 .51 .49 .51 ?