Can r lie outside the -1 and 1 range depending on the type of data?
No, the value of the correlation coefficient (r) cannot lie outside the range of -1 and +1, regardless of the type of data. The value of r always lies between minus one and plus one, i.e., -1 r 1.
If in any exercise, the value of r is found to be outside this range, it indicates an error in calculation. This property holds true for both the simple correlation coefficient and the rank correlation coefficient, as both lie between 1 and -1.
Explanation
The textbook explicitly states that 'The value of the correlation coefficient lies between minus one and plus one, -1 r 1. If, in any exercise, the value of r is outside this range it indicates error in calculation.' This is a fundamental mathematical property of the correlation coefficient and does not depend on the type of data. The context also confirms that the rank correlation coefficient shares this same property.