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 with a standard deviation of on a standardized test. Assuming a​ mound-shaped and symmetric​ distribution, in what range would approximately ​% of the students​ score?