Probabilities and time

  • Thread starter Niles
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  • #1
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Homework Statement


Hi all.

Say I roll a dice every 2 seconds. So in t seconds, I will have rolled the dice t/2 times. I want to find a way of knowing the mean value of the dice-throws (i.e. the mean number of eyes on the dice) as a function of the time t.

The Attempt at a Solution


Since there are equal probability of getting 1 .. 6, I would say the mean is just 3.5, and this is not dependent on time.


By the way, is there a difference between average and mean? The way I have understood it, the mean is the theoretical average of eyes when tossing the dice infinitely many times, while the average is looking at a specific series, i.e. the series 1, 3 and 5 has the average 3.

Thanks in advance.

Best regards,
Niles.
 

Answers and Replies

  • #2
HallsofIvy
Science Advisor
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The mean is the "arithmetic average" for a uniform probability distribution as you have here or a "weighted average" if not. Your distinction is between the distribution mean and sample mean, not between "mean" and "average".

And, as you calculated, if you roll a die a number of times, the overall mean is a constant, 3.5. It is independent of the number of times you roll the die.
 
  • #3
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Thanks.
 

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