Since 120 students gained less than 70, and 70 is the upper quartile, 120 people are in the 75% of all the students so we need to find the total number of students. we need to multiply 0.75 (75%) by something to get 120. which is 160 (the total number of all students). and since 48 is the median score, find 50% of 160 which is 80! hope this helps :)