TBH, yes, I actually don't get it. I haven't spend ages on it either but here you go...
OTOH, I am one of those dull bastard who tend to consider practical applications as one of the most important and most interesting part of any human endeavour...
That being said, I am getting twisted over a simple problem. Which shows how much I am out of training when it comes to anything mathematical. It's a probability issue mixed with an Excel question so turn your eyes away if you're one of those 'pure maths = beauty' guy...
The set up is as follow: I've got a certain amount of dice. I've got to roll 3 or better on them for it to be consider a success (i.e. probability of success
per dice is equal to 50%). The number of success to achieve is itself variable.
Example: I got 1 dice and I got to generate at least 1 success - Blindingly obvious, my probability of success is 50%. But what if I got 4 dice and I need 3 successes (at least - 4 successes are acceptable)? I could proceed by sheer counting but, well, isn't in order to avoid doing so we invented equations and then excel?
It seems to me this is a more or less straightforward Binomial distribution issue (although finding that out took me 10 mins on Excel Help. I am really out of practice!) The Excel formula is supposed to be written:
BINOMDIST(number_s,trials,probability_s,cumulative )
where: Number_s is the number of successes in trials. (here, I would say, this is the number of success I am trying to achieve).
where: Trials is the number of independent trials. (here, this is clearly the number of dice I am rolling).
where: Probability_s is the probability of success on each trial. (here, it is a fixed 50%)
where: Cumulative is a logical value that determines the form of the function. If cumulative is TRUE, then BINOMDIST returns the cumulative distribution function, which is the probability that there are at most number_s successes; if FALSE, it returns the probability mass function, which is the probability that there are number_s successes. (here, I would suggest that the value should be TRUE. I am OK with having 4 successes even if I wanted a minimum of 3).
But it doesn't work. And there's still one more stage to add to this (sometimes, the dice can be 'explosive'; That is to say, that rolling a 6 allow you to re-roll again to try and get another 'success'. Thus, if you're lucky, with 3 dices, you can beat a 4 or 5 obstacles. You need some 6s and you need to re-roll them above 3).
HELP!
Linear Mode
