Assume that adults have IQ scores that are normally distribu

Assume that adults have IQ scores that are normally distributed with a mean of 105 and a standard deviation 15. Find Upper P 14, which is the IQ score separating the bottom 14% from the top 86%.

Solution

Assume that adults have IQ scores that are normally distributed with a mean of 105 and a standard deviation 15. Find Upper P 14, which is the IQ score separating the bottom 14% from the top 86%.

Z value for bottom 14% = -1.08

The required IQ score=

= mean+z*sd

=105-1.08*15

= 88.8