fix typo in tutorial

docs/src/tutorial.md

@@ -12,7 +12,7 @@ x^c_t = \sin{\left(\frac{2\pi}{20}t + \psi\right)} + \frac{mt}{T} + \sigma_c n_t
 
 where ``m`` is the slope of a linear trend, ``\psi \in [0, 2\pi)`` is a uniformly random phase offset, ``\sigma_c`` is the noise scale, and ``n_t \sim \mathcal{N}(0,1)`` are  normally distributed random variables. 
 
-The two classes will be distinguished by their noise levels. The class one time series ``x^1`` have ``\sigma_1 = 0.1``, and the class two time series ``x^2`` have ``\sigma_2 = 0.5``. The below code sets this up
+The two classes will be distinguished by their noise levels. The class one time series ``x^1`` have ``\sigma_1 = 0.1``, and the class two time series ``x^2`` have ``\sigma_2 = 0.9``. The below code sets this up
 
 ```Julia
 # fix rng seed