UExcel Statistics 3

Question 1

What does R² (R-squared) represent in regression analysis?

Accepted Answer

The proportion of variance in the dependent variable explained by the independent variable

Answer

R² indicates the proportion of variance in the outcome variable that is explained by the predictor(s).

Question 2

Which of the following is an example of qualitative data?

Accepted Answer

Eye color categories

Answer

Qualitative (categorical) data describes characteristics or attributes, such as eye color categories.

Question 3

The law of large numbers states that:

Accepted Answer

As sample size increases, the sample mean approaches the population mean

Answer

The law of large numbers states that sample means converge to the population mean as sample size increases.

Question 4

What is a lurking variable?

Accepted Answer

An unmeasured variable that influences both the independent and dependent variables

Answer

A lurking (confounding) variable is an unmeasured factor that affects both variables under study, creating a false association.

Question 5

In a frequency distribution, relative frequency is calculated as:

Accepted Answer

Frequency divided by total number of observations

Answer

Relative frequency equals the class frequency divided by the total number of observations.

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