using a mean of 80 and a standard deviation of 12. a) what is the score that divides the distribution such that 99% of the area is below it. b) what are the scores that bound the middle 95% of the distribution

Answer 1

I find this webtool perfect for your kind of question

http://davidmlane.com/hyperstat/z_table.html

use the 2nd applet,
enter 80 in the mean
enter 12 in the sd
and .99 in the "shaded area" box

click on "below"