Final answer:
The statement "There are five calories in a stick of gum." is NOT a qualitative observation; it's a quantitative observation because it provides a numerical measurement.
Step-by-step explanation:
To answer which of the following is NOT a qualitative observation:
- The dog is black.
- There are five calories in a stick of gum.
- I love the color purple.
- The rainbow is very colorful.
The statement that is not a qualitative observation is "There are five calories in a stick of gum." This is because it includes a numerical value indicating a measurement, which makes it a quantitative observation. Qualitative observations describe properties or occurrences without the use of numbers. For example, stating that sulfur crystals are yellow is qualitative, while saying the melting point of sulfur is a specific temperature is quantitative.
In contrast, the descriptions stating the dog is black, expressing a preference for the color purple, and observing that a rainbow is very colorful are all qualitative because they describe without using any numbers.