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Scatter Graph Applicability: Analyzing Data Relationships
Published on July 6, 2026
Statistics
Determine if a scatter graph is suitable for representing different data sets, focusing on the requirement of two numerical variables. Explains why price vs. rooms is suitable, but heights alone or favorite animals vs. ages are not.
Question
Answer
To determine if a scatter graph can be used, we need to check if the data consists of two numerical (quantitative) variables for each individual item. A scatter graph is used to show the relationship (correlation) between two sets of numbers.
Here is the step-by-step analysis for each part:
a) The prices of houses and the number of rooms they have
- Analysis: “Price” is a numerical value (e.g.,
), and “number of rooms” is also a numerical value (e.g., rooms). Since we have two numerical variables for each house, we can plot them as coordinates. - Answer: Yes.
- Explanation: A scatter graph can be used because both the price and the number of rooms are numerical data types that can be plotted on an
and axis to show a correlation.
b) The heights of different people
- Analysis: “Height” is a numerical value. However, there is only one variable mentioned here. To make a scatter graph, you need a second variable (like weight or age) to compare against height. If you only have heights, you would use a histogram or a dot plot.
- Answer: No.
- Explanation: A scatter graph cannot be used because there is only one variable provided (height), and a scatter graph requires two different numerical variables to show a relationship.
c) People’s favourite animals and their ages
- Analysis: “Age” is a numerical value, but “favourite animal” is a categorical (qualitative) variable (e.g., “Dog”, “Cat”). You cannot plot a category like “Dog” on a standard numerical axis to find a mathematical correlation.
- Answer: No.
- Explanation: A scatter graph cannot be used because one of the variables (favourite animal) is categorical rather than numerical.