Can a correlation coefficient be greater than 1 or less than -1?

No, a correlation coefficient cannot be greater than 1 or less than -1. The range of values for a correlation coefficient is from -1 to +1. A correlation coefficient of -1 indicates a perfect negative correlation, meaning that the two variables move in opposite directions, while a correlation coefficient of +1 indicates a perfect positive correlation, meaning that the two variables move in the same direction.

If the correlation coefficient were to exceed +1 or fall below -1, it would imply that the variables are more than perfectly related, which is not possible. This would indicate a flaw in the data or in the statistical analysis, and it would require further investigation to identify the source of the error. Therefore, it's important to keep in mind that the range of values for the correlation coefficient is limited to -1 and +1.