If is a random variable representing test scores, then the 41st percentile is the score such that . Transform to the random variable that follows the standard normal distribution via :
The -score for the 41st percentile is about -0.2275, so
To solve this we are going to use the average rate of change formula: where is the average rate of change of the function is the position function evaluated at is the position function evaluated at is the first point in the interval is the second point in the interval
We can infer for our problem that the first point is 3 and the second point is 6, so and . Lets replace those values in our formula:
We can conclude that the average rate of change of the function f(x) = 1 x - x2 - 2 for <span>3 ≤ x ≤ 6 is -8</span>