I have been working on producing an excel spreadsheet to automatically calculate probability values for multiple independent events occurring.

Hopefully I find assistance in confirmation that the results acquired are correct - or at least on the right lines.

I do not come from a statistics background, so apologies in advance for any errors.

The spreadsheet can calculate the probability that either 2 or 3 events occur, from a total of up to 10 events. The calculations include multiplying each independent event (i.e. P(A n B) [2], P(A n B n C) [3].

Where 10 events are being calculated, the inputs rise dramatically - in line with the total number of events.

With this, the final calculation utilises probabilities of each 2-occurring/3-occurring combination. These probabilities are added together to produce a final probability value.

The best way to confirm accuracy/inaccuracy is to post an example calculation.

The below example contains 5 independent events, with probability displayed in decimal format.

Event 1 probability: 0.0333

Event 2 probability: 0.5000

Event 3 probability: 0.2325

Event 4 probability: 0.3077

Event 5 probability: 0.2222

The calculator produces the following values (again displayed as decimal probability):

Probability of any 2 events occurring: 0.6149

Probability of any 3 events occurring: 0.1308

These values appear extremely high, which is making me doubt the calculation.

Please may I request assistance in validating/altering the calculations to produce accurate probability values.

Sincerely,

Tulipan