Today we learned a new subject, ordered seats and repetitions allowed.
Let's say we put 5 balls in a box, then we pick 1 ball marked A and put it back,
we pick another ball (which could be the same ball marked A) and marked it B then put it back. So as it goes on by 5 times.
What's the probability that we mark A, B, C, D, E at the same ball?
This is different compared to the prior subjects of assigning seats, the repetitions is allowed, so we have 5 possibilities for first pick, and another 5 possibilities for each first pick and so on to the fifth pick.
So the possibilities to mark A, B, C, D, E at the same ball is
1/5 *1/5 *1/5 *1/5 *1/5 = 1/3125
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Today Sal schooled again what the variance is, so even the mean of the two samples are the same, the variance could be hugely different that causes the level of dispersion. The bigger the dispersion is, the more far each number of sample away the mean.
Okay, I am thinking maybe I should stop watching videos in the morning, that's kind of too wasted of time, hmm, I gotta think about it.
