Question 1

Which of the following best describes the primary purpose of a scatterplot in statistics?

Accepted Answer

To examine the relationship between two numerical variables.

Question 2

A scatterplot of age of used cars (x-axis) versus miles driven (y-axis) shows an upward trend as you move from left to right. Which of the following best describes this association?

Accepted Answer

Positive and linear

Question 3

When examining a scatterplot, which three features should you always describe?

Accepted Answer

Trend, strength, and shape

Question 4

A scatterplot shows that as literacy rate increases, total births per woman decreases. What type of association is this?

Accepted Answer

Negative association

Question 5

Which of the following statements is most appropriate when describing an association in a scatterplot?

Accepted Answer

Older cars tend to have higher mileage.

Question 6

A scatterplot of marathon running speed versus age shows no clear pattern. What does this indicate?

Accepted Answer

There is no association.

Question 7

Which of the following best describes a strong association in a scatterplot?

Accepted Answer

There is little vertical variation and the points cluster closely around a line or curve.

Question 8

Suppose you are analyzing the relationship between temperature and ozone levels. The scatterplot shows a curved upward trend. Which of the following best describes the shape of this association?

Accepted Answer

Non-linear

Question 9

Which of the following is NOT a correct step when describing an association between two numerical variables?

Accepted Answer

Assuming the association applies to every individual.

Question 10

A scatterplot of waist size (x-axis) and weight (y-axis) shows less vertical variation than a scatterplot of height and weight. What does this imply?

Accepted Answer

Waist size and weight have a stronger association than height and weight.

Question 11

Which of the following best describes a linear trend in a scatterplot?

Accepted Answer

The points form a straight line with some scatter.

Question 12

Why is it important to use phrases like 'tends to' when describing associations in scatterplots?

Accepted Answer

Because there is variability and the trend may not apply to all individuals.

Question 13

Which of the following is an example of a non-linear association?

Accepted Answer

A scatterplot where points follow a U-shaped curve.

Question 14

If a scatterplot shows a strong positive linear association, which of the following is most likely true?

Accepted Answer

As one variable increases, the other tends to increase.

Question 15

Which of the following best describes an outlier in the context of a scatterplot?

Accepted Answer

A point that is far from the general pattern of the data.

Question 16

A researcher creates a scatterplot of two variables and observes a football-shaped cluster of points. What does this suggest about the association?

Accepted Answer

The association is likely linear.

Question 17

Which of the following is a correct interpretation of a moderately strong positive linear association between age and mileage of used cars?

Accepted Answer

Older cars tend to have higher mileage, but there are exceptions.

Question 18

Which of the following best describes the difference between a strong and a weak association in a scatterplot?

Accepted Answer

A strong association has points that are closely clustered around a line or curve.

Question 19

Suppose you are analyzing the relationship between two variables and notice one data point that is far from the rest. What should you do when describing the association?

Accepted Answer

Mention the point as an unusual observation.

Question 20

Which of the following is the best way to summarize a scatterplot showing a non-linear association between temperature and ozone levels?

Accepted Answer

There is a non-linear association; as temperature increases, ozone levels tend to increase at an increasing rate.

Regression Analysis: Exploring Associations Between Variables

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