find out mean and median of following data marks 0-10 10-20 20-30 30-40 40-50 50-60 60-70 70-80 students 5 10 20 40 30 20 10 4
Answers
Answer:
Mean = 39.39 Median = 30.86
Explanation:
CI F X dx= X-A Fdx CF
0 - 10 5 5 - 30 - 150 5
10 - 20 10 15 - 20 - 200 15
20 - 30 20 25 - 10 - 200 35
30 - 40 40 35 0 0 75
40 - 50 30 45 10 300 105
50 - 60 20 55 20 400 125
60 - 70 10 65 30 300 135
70 - 80 4 75 40 160 139
139 610
∴ Mean = A+ ∑ Fdx Median= Size of Nth items
∑F 2
= 35 + 610
139 = Size of 139th items
= 35 + 4.39 2
= 39.39 = Size of 69.5th items
∴ Median lies in the class 30 - 40
∴ Me = L+ 69.5 - CF
F
= 30 + 69.5 - 35
40
= 30 + 0.86
= 30.86