Final answer:
Bivariate regression is the statistical technique among the given options which requires both variables to be either ratio or interval data, as it determines the linear relationship between two numerical variables.
Step-by-step explanation:
The question asks which of the following techniques requires that both variables are ratio or interval data: a) t-test, b) Bivariate regression, c) z-test, or d) ANOVA.
The correct answer is b) Bivariate regression. Bivariate regression is a statistical technique used to determine the linear relationship between two variables, both of which should be either interval or ratio in nature. This is because bivariate regression calculates the strength and direction of the relationship through a linear equation, necessitating that both the independent variable and the dependent variable have a numerical value that allows for this mathematical operation. Other options, like the t-test and z-test, can be used with ratio or interval data but also have versions that work with nominal or ordinal data. The ANOVA is mainly used to compare means across multiple groups and can handle ratio and interval data as well.
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