The scores from a state standardized test have a bell-shaped distribution with a mean of 100 and a standarddeviation of 15. Use the Empirical Rule to find the percentage of students with scores between 70 and 130.
A) 95%
B) 68%
C) 99.7%
D) 100%

Question

Quizplus · Accepted Answer

The Empirical Rule states that for a bell-shaped distribution, approximately 68% of the data falls within one standard deviation of the mean, 95% within two standard deviations, and 99.7% within three standard deviations. Scores between 70 and 130 are within two standard deviations (15*2 = 30) from the mean (100), so 95% of the scores fall within this range.

The Scores from a State Standardized Test Have a Bell-Shaped