On Fri, Nov 14, 2014 at 10:26:29AM -0600, Edgar Pettijohn wrote:
> > On January 15th each year Wietse sets a counter for the following
> > year's release to zero. Each day after that he rolls a 6 sided
> > dice, and adds the value to the running total. When the total
> > reaches 1278, a new release is cut. :-)
>
> So around August?
[ Off topic alert, move along... ]
Your arithmetic is different than mine.
$ echo "2k 1278 3.5 / p" | dc
365.14
Your task is to compute the variance, it is easy to compute the
variance of total after 365 days. I have not thought about how to
correctly compute the variance of the number of days needed to
reach a target total. A naive order of magnitude guess is to take
the variance of the expected total after 365 days and divice by
the mean increment per day. That gives a guestimated standard
deviation of ~sqrt(365 * 35/12)/3.5 or 9.5 days. Replace the dice
with a coin toss, how does that change the standard deviation? :-)
--
Viktor.
