# Empirical formula- 68%, 95.5%, & 99.9% of scores

I'm having trouble with some stats questions for my psychological testing paper. Have tried emailing the professor but to no avail. Given the standard deviation of 19.8,Identify the range of scores where you would expect to find 68,99.5,& 99.9% of the scores if there were a normal distribution. And then how does the distribution we obtained compare? The mean is 66 for this data set. I've been working on this paper for weeks (it's already over 20 pages long and I think my brain is just wiped out, for the life of me I can't seem to get an answer that makes since. I was sure this wasn't a normal distribution, but according to SPSS it meets the criteria.) If someone could solve it that would be amazing, I know the steps but somehow I'm lost.

• Please add the [self-study] tag & read its wiki. Then tell us what you understand thus far, what you've tried & where you're stuck. We'll provide hints to help you get unstuck. Please make these changes as just posting your homework & hoping someone will do it for you is grounds for closing. – Silverfish Dec 15 '15 at 1:08
• I assume you're in Holden's class? I'm looking for the same answer lol. – Ali Dec 15 '15 at 4:32
• What does the "empirical formula" you were given actually state? – Glen_b Dec 15 '15 at 4:50