Respuesta :
Answer:
95% of people have an IQ score between 72 and 128.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 100
Standard deviation = 14.
(a) What percentage of people has an IQ score between 72 and 128?
72 = 100 - 2*14
So 72 is two standard deviations below the mean.
128 = 100 + 2*14
So 128 is two standard deviations above the mean.
By the Empirical Rule, 95% of people have an IQ score between 72 and 128.
