Which of these is NOT an example of an interval scale?

An interval scale is a type of measurement scale where the difference between values is meaningful, and there is no true zero point. Temperature in Celsius is a classic example of an interval scale because the degrees represent equal intervals and zero degrees does not mean the absence of temperature.

In contrast, height in centimeters is measured on a ratio scale, not an interval scale. A ratio scale contains a true zero point, signifying the absence of the quantity being measured—in this case, zero height represents no height at all. This allows for the meaningful comparison of ratios, such as someone being twice as tall as someone else.

IQ scores are also typically treated as interval scales because differences between scores can be interpreted meaningfully, though there's debate about the validity of treating them strictly as such. The price of a product is likewise a ratio scale because it has a true zero point, indicating no cost.

Thus, the height option stands out as it does not belong to the interval scale category due to its foundational properties of having a true zero point and making ratio comparisons possible.