Posted by carly on Wednesday, November 21, 2012 at 2:52pm.
if a test has a mean of 150 and a standard deviation of 30, we know that:
a)50% of the respondents scored between 180 and 210
b)68% of the responents scored above 120
c)50% of the respondents scored between 120 and 210
d) 96% of the respondents scored between 90 and 210

statistics  PsyDAG, Thursday, November 22, 2012 at 12:54pm
Z = (scoremean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the various Z scores.