3. Given the set of data 65, 72, 74, 78, 84, 87, what is the correlation coefficient?

To calculate the correlation coefficient, you need pairs of data points for two variables. Without another set of corresponding data, we cannot calculate the correlation coefficient. The correlation coefficient measures the strength and direction of a linear relationship between two variables.

If you have a second set of data that corresponds to the given set, please provide it, and I'll be happy to guide you through the calculation.