Exam 13: Hypothesis Testing and Measures of Association for Variables Measured at the Interval-Ratio Level

Which of the following describes the slope (b) if a regression line is parallel to the horizontal axis of the scatterplot?

A regression slope (b) is 2.5. What does this slope tell us about the strength of the relationship between X and Y?

Knowing the value of someone's body mass index helps explain 9% of the variance in blood pressure. What is the value of Pearson's r for this association?

What is a special feature of the least-squares regression line?

Which statement about variables is among the key assumptions of correlation analysis?

What does squaring Pearson's r give us?

What visual piece of information can be included in a scatterplot to summarize the clarity of a pattern?

A researcher wants to understand whether age causes declines in sexual frequency among European adults. As a first step in understanding this association, she makes a scatterplot. Which variable belongs on the Y (vertical) column?

Which of the following indicates the existence of an association between variables on a scatterplot?

We wish to test whether the correlation between two variables is significantly different from 0 (i.e., no relationship between X and Y in the population). When we look at the scatterplot of our data, we find that values of Y are tightly clustered together at low values of X, but much more spread out at high values of X. What assumption have we violated?

Suppose we want to know the association between Spotify song listens and touring revenues of punk bands. What would be the most appropriate measure of association to use?

Identify one similarity and one difference between least-squares regression and correlation coefficient (r).

Researchers wish to understand the strength of relationship between the digital readership of 80 North American newspapers (average Web page views per month) and the average age of the staff of those newspapers. What would be the most appropriate measure of association?

Suppose that the slope of a regression line is 1.5. How should this number be interpreted?

Suppose a correlation of r = 0.12 fails to fall within the critical region for a hypothesis test. Which of the following should be concluded?

According to the text, what could an analyst do if she intends to document an association between two interval-ratio variables that have a clearly non-linear relationship?

Which of the following best represents r²?

A study finds a Pearson's r value of -0.22 between proportion of women in management and sexual harassment claims in a sample of 425 company corporate offices. Which of these statements is the best interpretation of that finding?

A scatterplot line crosses the Y axis at "5" and is completely horizontal across the full range of X. Which of these statements best describes the relationship between X and Y?

For the least-squares regression equation , what does indicate?