The grades on the last art exam had a mean of 75%. assume the population of grades on art exams is known to be distributed normally, with a standard deviation of 7%. approximately what percent of student earn a score between 75% and 82%?

37.2%
84.1%
34.1%
50%

Determine the z-scores of the 75% and 82% by using the equation,
                                     z-score = (data - mean) / standard deviation

z-score of 75%
                                   z-score = (75 - 75)/(7)
                                                = 0 
This translates to a percentile of 50%

z-score of 82%
                                     z-score = (82 - 75) / (7)
                                                  = 1
This translates to a percentile of 84.13%

To determine the answer to this item, we have to get the difference between the two percentiles. This gives us the answer of 34.13%.

Thus, the answer is the third choice.