The mean IQ among members of a club is 118 with a standard deviation of 9.46. What percentage of the members had IQ scores of 115 or higher?

Answer 1

try this applet instead of looking up your z-scores in a table or chart, you will love it

You can enter the z-scores , or the data as it stands

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

Answer 2

The applet is great! But I wonder, given the information I have, can I assume that the distribution is normal? (The mean IQ among members of a club is 118 with a standard deviation of 9.46. What percentage of the members had IQ scores of 115 or higher?) If it isn't normal - I can't determine the percentage ... or can I?