Construction of frequency distribution - SS1 Economics Past Questions and Answers - page 1
What is the purpose of frequency distribution in economic analysis?
To organize data into classes
To calculate the mean
To find extreme values
To create a scatter plot
Which of the following is not a step to construct a frequency distribution
Determine the range of the data
Decide on the number of intervals (or classes)
Determine the average value of the set of data
Determine the width of the intervals
Suppose a teacher wants to analyze the test scores of their students in a math class. The scores range from 0 to 100, and there are 30 students in the class. The teacher groups the scores into intervals of 10 points each (0-9, 10-19, 20-29, and so on). The following table shows the frequency distribution of the test scores:
|
Interval |
Frequency |
|
0 - 9 |
2 |
|
10-19 |
4 |
|
20-29 |
6 |
|
30-39 |
5 |
|
40-49 |
3 |
|
50-59 |
5 |
|
60-69 |
2 |
|
70-79 |
2 |
|
80-89 |
1 |
Find the percentage of students who scored less than 50 on the test.
To solve the problem, we need to add up the frequencies for the intervals 0-9, 10-19, 20-29, 30-39, and 40-49, since these are the intervals where the scores are less than 50. The total frequency for these intervals is:
2 + 4 + 6 + 5 + 3 = 20
Therefore, 20 out of the 30 students scored less than 50 on the test. To find the percentage, we divide 20 by 30 and multiply by 100:
(20/30) x 100 = 66.67%
So, 66.67% of the students scored less than 50 on the test.