The sat and act college entrance exams are taken by thousands of students each year. the mathematics portions of each of these exams produce scores that are approximately normally distributed. in recent years, sat mathematics exam scores have averaged 480 with standard deviation 100. the average and standard deviation for act mathematics scores are 18 and 6, respectively. an engineering school sets 550 as the minimum sat math score for new students. what percentage of students will score below 550 in a typical year?