title: Math.floor(Math.random*myArray.length) is returning NaN
body: <p>I'm receiving a bit of a strange error. </p>
  
  <p>I'm trying to select the index of an array at random, so to do this I am using the code below: </p>
  
  <p><code>myArray[Math.floor(Math.random*myArray.length)]</code> </p>
  
  <p>myArray.length is 282, but <code>Math.floor(Math.random*myArray.length)</code> is NaN and <code>myArray[Math.floor(Math.random*myArray.length)</code> is undefined. </p>
  
  <p>Any thoughts? </p>