Describing Data with Tables and Graphs

Describing Data with Tables and Graphs

1. Frequency Tables

• When we collect raw data, it is often unorganized and difficult to interprete. To make the data meaningful, we summerize it by showing how often each value occurs. This is done using frequency table.

• Definition: A frequency table is a way of organizing data to show how many times(frequency) each value or group of values occur in dataset.

• For example ‒ Consider, following are the marks of students out of 100.

25, 35, 40, 42, 45, 46, 47, 50, 52, 55, 57, 58, 60, 63, 65, 66, 67, 68, 70, 72, 73, 74, 75, 77, 78, 80, 82, 85, 88, 90.

The frequency table can be prepared for this data and it is as follows –

Important observation: Most students scored between 60‒79 because this has highest frequency.

2. Graphs

1. Line chart: A line chart shows data points connected by lines. It's great for visualizing trends over time. It shows increase or decrease in the data. For example ‒ Tracking monthly sales of a product throughout the year.

2. Bar chart: A bar chart uses rectangular bars to represent data. It's useful for comparing different categories. For example ‒ Number of students attended different

3. Scatter plot : A scatter plot uses dots to represent the relationship between two variables. It helps to identify correlations.

4. Pie chart: A pie chart represents data as slices of a pie. Each slice shows a proportion of the whole. For example ‒ Popularity of various mobile brands can be represented by using pie chart.

5. Table chart: A table chart organizes data into rows and columns. It's useful for precise, detailed information. For example: Showing student grades.

6. Histogram: A histogram shows the distribution of a dataset. It uses bars to represent the frequency of data within certain intervals. For example: Showing the distribution Indeed e of test scores.

7. Lollipop chart: A lollipop chart is similar to a bar chart but with circles at the ends of the bars. It's useful for a cleaner look. For example ‒ Comparing the heights of different buildings.

Review Question

1.What is the main purpose of creating a frequency table?