Use the Empirical Rule to Describe Data That Are Bell Shaped
-A study was designed to investigate the effects of two variables - (1) a student's level of mathematical anxiety and (2) teaching method - on a student's achievement in a mathematics course. Students who had a low level of mathematical anxiety were taught using the traditional expository method. These students obtained a mean score of 490 with a standard deviation of 20 on a standardized test. Assuming a bell-shaped distribution, where would approximately $68 \%$ of the students score?
A) between 470 and 510
B) between 450 and 530
C) below 450 or above 530
D) below 470 or above 510

Question

Quizplus · Accepted Answer

The Empirical Rule states that for a bell-shaped distribution, approximately 68% of the data will fall within one standard deviation of the mean. Given a mean score of 490 and a standard deviation of 20, one standard deviation above and below the mean would be 490 + 20 = 510 and 490 - 20 = 470, respectively. Therefore, approximately 68% of the students would score between 470 and 510.

Use the Empirical Rule to Describe Data That Are Bell 68%68 \%68%

Use the Empirical Rule to Describe Data That Are Bell $68 \%$