Using the Empirical Rule, it is found that the proportion of people in a population with IQ scores between 80 and 140 is of 0.95 = 95%.
<h3>What does the Empirical Rule state?</h3>
It states that, for a normally distributed random variable:
Approximately 68% of the measures are within 1 standard deviation of the mean.
Approximately 95% of the measures are within 2 standard deviations of the mean.
Approximately 99.7% of the measures are within 3 standard deviations of the mean.
Considering the mean of 110 and the standard deviation of 15, we have that:
80 = 110 - 2 x 15.
140 = 110 + 2 x 15.
These values are both the most extreme within 2 standard deviations of the mean, hence the proportion of people in a population with IQ scores between 80 and 140 is of 0.95 = 95%.
Its in the format y=mx+b, where m is the slope and b is the intercept. Also since x is 0 at the y intercept, you could substitute 0 for x and see the intercept
