standard_description: Recognize that a measure of center for a numerical data set summarizes all of its values with a single number, while a measure of variation describes how its values vary with a single number.
problem_activity: Problem 1
Below is a normal distribution that shows the height of 8-year-old boys in inches. The relative frequency of each height is shown along the
$${y-}$$
axis, and the height, in inches, is shown along the
$${x-}$$
axis.
The mean is 50 and the standard deviation is 2.
[IMG]
Estimate the percent of 8-year-old boys chosen randomly who will be shorter than 53 inches.
Problem 2
The mean combined score for last year’s SAT was 1083 with a standard deviation of 193. The mean and the standard deviation are based on students who took the SAT across the nation.
If you took the SAT and scored a combined score of 1100, what percent of students who took the SAT scored below you?


aligns: no