Question

Question 7 The runs scored by two teams A and B on the first 60 balls in a cricket match are given below:

Number of balls Team A Team B
1 − 6 2 5
7 − 12 1 6
13 − 18 8 2
19 − 24 9 10
25 − 30 4 5
31 − 36 5 6
37 − 42 6 3
43 − 48 10 4
49 − 54 6 8
55 − 60 2 10

Represent the data of both the teams on the same graph by frequency polygons. [Hint: First make the class intervals continuous.]

Class 9 - Math - Statistics Page 260"

Answer 1

A frequency polygon is the polygon obtained by joining the midpoints of upper horizontal sides of all the rectangles in the histogram. Frequency polygons can also be drawn independently without drawing histogram.

 For this we first find class mark of a class interval by using the formula

Class mark=( upper limit + lower limit) /2

Here, the given frequency distribution is not continuous as it is in inclusive form(0-10, 11-20).

To Convert the intervals in continuous form firstly we find  the difference between upper limit of a class and the lower limit of its succeeding class then add and subtract half of this difference to upper limit and lower limit..

For continuous distribution we get first interval as

(1-0.5) – (6+0.5)= 0.5 -6.5.

Class mark of first interval= (0.5+6.5)/2= 7.0/2= 3.5

First we make the class intervals continuous & find the class marks of all the class intervals & the modified table of given data is in the attachment.

 

Now frequency polygon for both teams are in the attachment.

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Hope this will help you.....

Answer 2

This is the solution......
I hope it will help.....