Causation and correlation video lesson

What is the primary purpose of a scatter plot in statistics?

• To display the frequency distribution of a single variable.

• To show the relationship between two continuous variables.

• To compare parts of a whole.

• To illustrate changes in data over time.

In the linear relationship described by y = mx + b, what does 'm' (the slope) represent?

• The starting value of y when x is zero.

• The strength of the relationship between x and y.

• The change in y for every one-unit increase in x.

• The overall average of the data points.

What does correlation measure between two variables?

• Only the direction of their movement.

• Only the closeness of their movement.

• Both the direction and closeness of their movement.

• The cause-and-effect relationship between them.

On a scatter plot divided into four quadrants by the means of two variables, where would most points be located if there is a negative correlation?

• Mainly in the upper-right and lower-left quadrants.

• Mainly in the upper-left and lower-right quadrants.

• Evenly distributed across all four quadrants.

• Clustered around the center where the mean lines intersect.

What does a correlation coefficient (r) of 0 indicate?

• A strong positive linear relationship.

• A strong negative linear relationship.

• No linear relationship.

• A perfect non-linear relationship.

What is true about the relationship between the steepness of a regression line and the correlation coefficient?

• A steeper line always indicates a higher correlation.

• The steepness of the line is directly proportional to the correlation coefficient.

• Changing the units of measurement can alter the line's steepness without changing the correlation.

• A flat line always indicates zero correlation.

If the squared correlation coefficient (r^2) between two variables is 0.7, what does this imply?

• 70% of the variation in one variable is caused by the other.

• 70% of the variance in one variable can be predicted by the other.

• There is a 70% chance that the two variables are directly related.

• The correlation coefficient (r) is exactly 0.7.

When two variables, A and B, are correlated, which of the following is NOT necessarily true?

• A causes B.

• B causes A.

• A third variable (C) causes both A and B.

• The correlation implies a direct causal link between A and B.