Answer:
(a) range = difference between highest
mark and lowest mark
range of marks = 10 - 6
= 4
(b) total students = marks × frequency
(6×5)+(7×4)+(8×7)+(9×10)+(10×4)
= 30+28+56+90+40
= 244 students
(c) total frequency = 5+4+7+10+4
= 30
mean mark = total students/total
frequency
= 244/30
= 8.133