Hello all,

This is a straight forward (or so I thought) textbook question. I'll quote it word for word so I don't leave anything out.

You will need to look at this distribution of Reaction Times for the question:

http://img.photobucket.com/albums/v6...tablegraph.jpg
The question is then:

"By simple counting, you can calculate exactly what percentage of the sample lies above or below +/- 1, 1.5, 2, 2.5, and 3 Standard Deviations using the tables/graphs. You can also calculate, from the normal distribution table, what percentage of scores would lie above or below those cutoffs if the distribution were perfectly normal. Calculate these values and consider the implications of using a normal distribution to approximate a distribution that is not normal. Where are you off by a quite a bit, and where are you reasonably acurrate? Consider this from the point of view of both one-tailed and two-tailed areas. How would your answers change if the sample had been very much larger or smaller?"

The Mean of this distribution is: 60.26

The Standard Deviation of this distribution is: 13.01

N=300

Distribution is obviously not normal.

I have no idea what this question wants me to do exactly. If anyone can decipher the steps exactly I need to do to answer this question so I can receive full credit, I will forever be in your debt. I'm pretty sure I can manage the actual math behind it, but I just need clear instruction. You know its bad when your professor dislikes the text because of its poor wording. so again, a general outline of what I need to do to answer this fully will be much appreciated. If possible, if you can do an example of how this question needs to be answered using +/- 1SD, I'm sure I can follow the rest.

Thank you so much in advance.

James