2) The relative frequency is calculated by dividing each frequency by the total number of items in the sample. Thus, we have
Total number of test scores = 30
Score frequency relative frequency
50 - 59 4 4/30 = 0.13
60 - 69 2 2/30 = 0.07
70 - 79 7 7/30 = 0.23
80 - 89 10 10/30 = 0.33
90 - 99 7 7/30 = 0.23
Total = 30 0.99