Page 6 - Lesson note-4- Ch 14 Statistics( Frequency Polygon)

Example 5.

It can be observed that the class intervals of the given data are not continuous. There is
a gap of 1 in between them. Therefore, =0.5 has to be added to the upper-class limits
and 0.5 has to be subtracted from the lower-class limits.

Each interval can be found by using the following formula.

Class mark = 1 + 2
2
No. of balls Class mark C.I(Exclusive) Team A Team B
C.I(Inclusive)
1-6 3.5 -0.5-6.5 2 5
7-12 9.5 6.5-12.5 1 6
13-18 15.5 12.5-18.5 8 2
19-24 21.5 18.5-24.5 9 10
25-30 27.5 24.5-30.5 4 5
31-36 33.5 30.5-36.5 5 6
37-42 39.5 36.5-42.5 6 3
43-48 45.5 42.5-48.5 10 4
49-54 51.5 48.5-54.5 6 8
55-60 53.5 54.5-60.5 2 10