Question

Find the median by drawing both type of ogive, class interval :50-60 60-70 70-80 80-90 90-100 ,frequency :3 5 9 12 6

Answer 1

The median from O give ≈ 80.5 .

Step-by-step explanation:

The given table:

Classs Interval   Frequency        c.f.            Ogive

50-60                   3                         3              35

60-70                   5                         8               32

70-80                   9                        17               27

80-90                 12                        29              18

90-100                6                         35              6

Total                  35

∴ $\dfrac{N}{2} =\dfrac{35}{2} =17.5$

The cumulative frequency just greater than 17.5 is 29 and corresponding class is 80-90.

∴ l = 80, cf = 17 and h = 10

Median = $l+\dfrac{\dfrac{N}{2}-c.f. }{f}$

∴ Median = $80+\dfrac{17.5-17 }{12}\times10$

= 80 + 0.42

= 80.42

Hence, the median from O give ≈ 80.5 .