Question

to determine how strong a correlation is between two variables, we can compute a correlation coefficient. or we can check to see if the scatterplot is sloping upward or downward. or we can consider a third variable for the correlation. or we can examine the spread of the scatterplot. or we can see if the dependent variable is different for the experimental group and the control group.

Explanation:

The correlation coefficient measures the strength and direction of the linear relationship between two variables. A scatter - plot's upward or downward slope only shows direction, considering a third variable is for causal analysis, the spread of a scatter - plot is related to variance, and comparing dependent variables between experimental and control groups is for experimental analysis.

Answer:

No option is correct as only computing a correlation coefficient determines the strength of the correlation between two variables.