can someone explain this?
The following is a frequency data set for test scores in a small class. Construct a cumulative frequency plot displaying data. Then describe the graph in a sentence or two.
test scores:
40-49:1
50-59:2
60-69:2
70-79:7
80-89:9
90-99:5
cumulative:
49 1
59 3
69 5
79 12
89 21
99 30
so graph that. Now describe it.
To construct a cumulative frequency plot, you need to calculate the cumulative frequency for each score range. The cumulative frequency is the total frequency of all scores up to the current range. Here's how you can do that:
1. Start by listing the score ranges vertically on the left side of a graph paper or a spreadsheet. In this case, the ranges are 40-49, 50-59, 60-69, etc.
2. Next to each range, write the frequency of scores in that range. For example, for 40-49, the frequency is 1.
3. Calculate the cumulative frequency by adding up the frequencies from the first range to each subsequent range. For instance, for 40-49, the cumulative frequency is 1. For 50-59, the cumulative frequency is 1 + 2 = 3. Continue this calculation for each range.
4. Plot the cumulative frequencies on a graph. The cumulative frequency will be on the y-axis, and the score ranges will be on the x-axis.
5. Connect the plotted points to form a line to represent the cumulative frequency plot.
In this case, your cumulative frequency plot will have five points: (40-49, 1), (50-59, 3), (60-69, 5), (70-79, 12), and (80-89, 21). The graph will show an increasing trend as the scores increase, indicating that more students achieved higher scores.
To describe the graph in a sentence or two, you can say something like: "The cumulative frequency plot shows that there is a gradual increase in the number of students who scored within each score range. The plot reveals that a significant majority of students achieved scores above 70, with the highest frequency observed in the 80-89 score range."