Gary drives to work everyday, and estimated the probability that he gets a red light at a particular intersection is 3/10. He based this on his last 10 trips.

Question

I need to carry out  a simulation on excel spreadsheet on my case to obtain the number of red lights he will encounter at this intersection on his next 100 trips. Can anyone help please.

 

Thanks

Answer 1

I put this formula in A1 and extended it down to A100:

 

=CHOOSE(RANDBETWEEN(1,10),"R","R","R","G or Y","G or Y","G or Y","G or Y","G or Y","G or Y","G or Y")

 

There are 3 "R"s and 7 "G or Y"s, giving a 30% possibility of choosing an R, or Red light (as opposed to Green or Yellow".  Then, I count the Rs using -

 

=COUNTIF(A1:A100,"R")

 

Press the F9 key repeatedly (to recalculate the sheet, and thus regenerate the random values).  Watch the count of Rs and it should hover close to 30.