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# A z-score

A z-score, in simple terms, is a score that expresses the value of a distribution in standard deviation with respect to the mean. Let's take a look at the following formula that calculates the z-score: Here, X is the value in the distribution, µ is the mean of the distribution, and σ is the standard deviation of the distribution

Let's try to understand this concept from the perspective of a school classroom.

A classroom has 60 students in it and they have just got their mathematics examination score. We simulate the score of these 60 students with a normal distribution using the following command:

```>>> classscore
>>> classscore = np.random.normal(50, ...```

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