Instructions

1. Clone the repository to your local development environment https://github.com/simple-statistics/simple-statistics
2. git checkout to tag v7.7.2

Description of the bug

The mean() function does not raise an error for null values in sample, nor is there a note in the documentation specifying this.

Here's an example of where I realized this:

  const ss = require("simple-statistics");
  
  var x = [null, 30, null];
  console.log(ss.mean(x));
  
  # which returns: 10

Expected behavior

When passing in NaN, nulls, strings, or undefined values to the function, the result should be NaN.