I think I know how to answer the following question IF I assume that the distribution is normal - however, since the question doesn't say that it comes from a normal distribution - should I proceed differently?
Question reads: 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?
My response,66.3% as follows: Find Z-score of 114 since question asks about 115 or higher (Z=-.42), look up .42 in Z Table (16.28) and add to 50% (66.28%).
Statistics - Is it from Normal Distribution - bobpursley, Wednesday, April 28, 2010 at 3:35pm
IQ is a normal gaussian distribution.