Question

Class interval No. of student
10-25, 2,
25-40, 3
40-55 7
55-70, 6
70-85, 6
85-100 6
Fine the Mean? ​

Answer 1

Class interval Mean Class Interval Frequency Deviation

10-25 17.5 2 -30

25-40 32.5 3 -15

40-55 47.5=A 7 0

55-70 62.5 6 15

70-85 77.5 6 30

85-100 92.5 6 45

Mean deviation = 6

2×(−30)+3×(−15)+6×15+6×30+6×45=6

−60−45+90+180+270

=72.5