The mean score of a mathematics placement exam is 125 with a standard deviation of 12.51. those who score i the bottom 20% are required to take a remedial course. assuming the data are not normally distributed, what is the lowest score you can get and not have to take the remedial math class?

You're looking for such that



Transforming the standard normal distribution, you have



where is the cutoff score in terms of this new distribution. The z-score corresponding to a probability of 0.20 is approximately , which means the cutoff test score is



Rounding to the nearest whole point, a score of about 114 is the bare minimum requirement to not have to take the remedial course.