Answer: 2.5% of people have an IQ over 126.
Step-by-step explanation:
Given: The distribution of IQ (Intelligence Quotient) is approximately normal in shape with a mean of 100 and a standard deviation of 13.
126 = 100 + 2(13) = Mean +2 ( standard deviation)
To find : % of people have an IQ over 126.
i.e. % of people have an IQ over Mean +2 ( standard deviation).
According to the standard deviation rule,
95% of data fall within two standard deviations.
Now, 100% - 95% = 5%
and Half of 5% is 2.5%.
So 2.5% of the data lies below 2 standard deviations of mean and 2.5% of the data lies above 2 standard deviations of mean .
i.e. 2.5% of people have an IQ over 126.
