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

The slope of the regression line

Answer

The correlation between residuals

Answer

The standard error of the estimate

Question 2

Which of the following is an example of qualitative data?

Accepted Answer

Eye color categories

Answer

Height in centimeters

Answer

Test scores

Answer

Number of students in a class

Question 3

The law of large numbers states that:

Accepted Answer

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

Answer

Larger samples always have less variance

Answer

All large samples are normally distributed

Answer

Larger datasets always produce smaller p-values

Question 4

What is a lurking variable?

Accepted Answer

An unmeasured variable that influences both the independent and dependent variables

Answer

The variable being measured in an experiment

Answer

A variable with no variance

Answer

An outlier in a dataset

Question 5

In a frequency distribution, relative frequency is calculated as:

Accepted Answer

Frequency divided by total number of observations

Answer

Frequency divided by class width

Answer

Frequency multiplied by class width

Answer

Cumulative frequency divided by total observations

Question 6

Which of the following describes a positively skewed distribution?

Accepted Answer

The tail extends to the right

Answer

The tail extends to the left

Answer

The mean equals the median

Answer

The distribution has two peaks