Week 2. Expected value of a function - 2nd example

Course Q&A Math for Machine Learning Probability & Statistics for Machine Learning &...
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Link to the classroom item I am referring to: https://www.coursera.org/learn/machine-learning-probability-and-statistics/lecture/6uZiQ/expected-value-of-a-function

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I think I’m missing something really simple here. Can anyone explain me how the wins are calculated here in the second example of the video? If a person in paying 5$ to start playing and then receives 2 times the value of the dice, then doesn’t it has to be the following?

  • Roll: 1 → (2 · 1) - 5 = -3
  • Roll: 2 → (2 · 2) - 5 = -1
  • Roll: 3 → (2 · 3) - 5 = 1
  • Roll: 4 → (2 · 4) - 5 = 3
  • Roll: 5 → (2 · 5) - 5 = 5
  • Roll: 6 → (2 · 6) - 5 = 7

So then the expected value of the example function is: 2

2 Likes
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Sorry for the delay. Do you need help with this question?

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Can anyone explain ?? I am having the same doubt!!!

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Yes I need the help!!!

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You are correct, that’s a glaring error in the video.

I’ll submit a ticket to see if it can be fixed.

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@JP_X, thanks for this post. My head was spinning trying to make sense of this topic in the video.

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I was going crazy with this video. Then I found the post from JP_X and reply from TMosh. Surprised the video and slide have not been fixed - almost a year later.

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Apparently, fixing videos that feature a guest lecturer is a non-trivial process.