Which of the following best describes the difference between $univariate$ data and $bivariate$ data?

• A. $Univariate$ data is used only for probability distributions, while $bivariate$ data is used only for hypothesis testing.
• B. $Univariate$ data requires two samples, while $bivariate$ data requires only one sample.
• C. $Univariate$ data consists of observations on a single variable, while $bivariate$ data consists of observations on two variables for each subject.
• D. $Univariate$ data always involves categorical variables, while $bivariate$ data always involves numerical variables.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the definition of univariate data. Univariate data consists of observations on a single variable. This means each data point represents one characteristic or measurement for each subject or unit.
2. Step 2: Understand the definition of bivariate data. Bivariate data consists of observations on two variables for each subject or unit. This allows us to study the relationship or association between these two variables.
3. Step 3: Analyze the options given in the problem. The first option incorrectly associates univariate data only with probability distributions and bivariate data only with hypothesis testing, which is not accurate.
4. Step 4: The second option incorrectly states that univariate data requires two samples and bivariate data requires only one sample, which confuses the concept of variables with samples.
5. Step 5: The fourth option incorrectly claims that univariate data always involves categorical variables and bivariate data always involves numerical variables, which is not true since both types of data can be categorical or numerical.