Mean = ∑fx/N
= [(90-99)*12 + (80-89)*22 + (70-79)*20 +(60-69)*14 + (50-59)*14 + (40-49)*4 + (30-39)*2]/75
= 6638/75
= 88.5 (approx.)
Median = Middle value when scores are arranged in ascending order
= (70-79)
= 75/2 = 37.5th term
= 75th term lies between 70-79
Median = 75
Mode = Value that repeats maximum number of times
= 80-89 (occurs 22 times)
So, mean = 88.5
median = 75
mode = 80-89