Let's see, 81 minus 65 is what? It is 5 plus 11, it's 16. So this is going to be minus 16 over 6.3. And take our calculator out, and let's see, if we have minus 16 divided by 6.3, you get minus 2.54. So approximately equal to minus 2.54. That's the z-score for a grade of 65. Pretty straightforward.