Using Empirical Rule 3.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 460 with a standard deviation of 40 on a standardized test. Assuming a bell-shaped distribution... a) What two scores would approximately 68% of the scores fall between? b) Approximately 99.7% of the scores fall between fall between what scores? c) What percentage of scores fall between 380 and 540? 99.7% 95.5% 68% 0.13% 2.14% 13.59% 34.13% 34.13% 13.59% 2.14% ! 0.13% +30 +4a -40 -30 -20 -lo +1o +20 Scores: 460 4. The scores from a state standardized test have a bell-shaped distribution with a mean of 100 and a standard deviation of 15. Use the Empirical Rule to find the following. a) What percentage of students have scores between 70 and 130? b) What percentage of students have scores between 55 and 115? c) What two scores does approximately 99.9% of the fall between? 99.9% 99.7% 95.5% 68% 0.13% 2.14% 13.59% 34.13% 34.13% 13.59% 2.14% 0.13% -40 -30 -20 -lo +1o +20 +30 +40 Scores: 100