Question

Assume that adults have a IQ score that are normally distributed with a mean of 99.4 and a standard deviation of 16.7. Find the first quadrille Q one which is the haiku score separating the bottom 25% from the top 75%

Answer 1

Explanation:

Look at negative z-score table ....looking for .2500 (25%)

Z score = - 2.81 or 2.81 Standard deviations (16.7) BELOW the mean

99.4 - 2.81 * 16.7 = 52.5 IQ score