Regarding the normal curve and standard deviation, which of the following statements is/are TRUE?
A)The standard deviation measures offset proportions of a normal curve that are above and below the mean.
B)The distribution of chance events typically resembles a normal curve.
C)The relationship of the standard deviation to the normal curve does not change, which makes it possible to compare groups of scores from distributions that are approximately normal.
D)All of these statements are true.

Question

Quizplus · Accepted Answer

All three statements are true. The standard deviation measures the spread or variability of scores in a distribution, and it also provides information about the proportion of scores that fall within certain intervals on a normal curve. Normal curves are often used to model chance events because many natural phenomena follow a normal distribution. Because the standard deviation has a fixed relationship to the proportions of a normal curve (e.g., 68% of the scores fall within one standard deviation of the mean), it is possible to compare scores from different distributions that are approximately normal.

Regarding the Normal Curve and Standard Deviation, Which of the Following