feat: add a more practical example course

exampleSite/content/courses/example/stats.md

@@ -0,0 +1,33 @@
+---
+title: Statistics
+date: '2021-01-01'
+type: book
+weight: 40
+math: true
+---
+
+Introduction to statistics for data science.
+
+<!--more-->
+
+{{< icon name="clock" pack="fas" >}} 1-2 hours per week, for 8 weeks
+
+## Learn
+
+The general form of the **normal** probability density function is:
+
+$$
+f(x) = \frac{1}{\sigma \sqrt{2\pi} } e^{-\frac{1}{2}\left(\frac{x-\mu}{\sigma}\right)^2}
+$$
+
+{{< callout note >}}
+The parameter $\mu$ is the mean or expectation of the distribution.
+$\sigma$ is its standard deviation.
+The variance of the distribution is $\sigma^{2}$.
+{{< /callout >}}
+
+## Quiz
+
+{{< spoiler text="What is the parameter $\mu$?" >}}
+The parameter $\mu$ is the mean or expectation of the distribution.
+{{< /spoiler >}}