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← Convert to Popularity Score - Intro to Descriptive Statistics

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Showing Revision 3 created 05/25/2016 by Udacity Robot.

  1. Well, we have that the z-score is 0.56 and we want to find out what value

  2. corresponds to this in a normal distribution with mean of 50 and a standard
  3. deviation of 10. So here, we have our setup, so all we do is multiply 0.56 by 10
  4. and then add 50. So this gives us 55.6, so basically, what we did is we took a
  5. pretty spread out distribution with mean 190 and standard deviation 36. We
  6. converted it to the standard normal distribution with mean of 0 and standard
  7. deviation 1. And then, we converted that to a normal distribution with mean of
  8. 50 and standard deviation 10. So the score for each of these distributions
  9. corresponds with the same percentage less than that score. So a score of 210,
  10. here, the proportion less is exactly the same as a score of 0.56 here. And
  11. that's exactly the same as the proportion less than a score of 55.6 in this
  12. distribution. Hopefully, that makes sense, and if it doesn't, don't worry. It's
  13. going to make more and more sense as you get used to working with normal
  14. distribution. And in the next lesson, you're going to learn how to calculate the
  15. percentages less than or greater than certain values on the x-axis. Good job.