Which of the following statements is not typically included in the description of a scatter diagram?

• A. The $\mathrm{mean}$ and $\mathrm{standard} \mathrm{deviation}$ of each variable
• B. The form or pattern of the data points (such as linear or nonlinear)
• C. The strength of the association between the variables
• D. The direction of the relationship between the two variables

Answer: (A)

Verified step by step guidance

1. Understand that a scatter diagram (or scatter plot) is a graphical representation used to visualize the relationship between two quantitative variables by plotting data points on a Cartesian plane.
2. Recognize that typical descriptions of a scatter diagram include: the form or pattern of the data points (e.g., linear, nonlinear), the strength of the association (how closely the points cluster around a form), and the direction of the relationship (positive, negative, or no clear direction).
3. Note that while the mean and standard deviation are important descriptive statistics for individual variables, they are not typically described as part of the scatter diagram itself, since the scatter plot focuses on the relationship between variables rather than their individual distributions.
4. Therefore, identify that the statement 'The mean and standard deviation of each variable' is not usually included in the description of a scatter diagram, as it pertains to univariate statistics rather than the bivariate relationship shown in the scatter plot.
5. Summarize that the key elements of a scatter diagram description are form, strength, and direction of the relationship, but not the mean and standard deviation of each variable.