20. What is an example of an interval variable?
Answer: C
Room temperature (in Fahrenheit) in a study about stress is an example of an interval variable.
Interval variables are numeric variables where the order and the exact differences between the values are meaningful. Room temperature measured in Fahrenheit is an interval variable because it has a consistent scale, where the difference between any two temperatures can be quantified.
A) Color preference in a study about geographic influences
Color preference is a nominal variable because it categorizes responses without a numerical order or meaningful differences between categories. There is no inherent ranking or quantifiable difference in preferences that would classify it as an interval variable.
B) Perceived level of satisfaction in a study about customer service
Perceived level of satisfaction is typically measured on an ordinal scale, where the values indicate a ranking (e.g., from very dissatisfied to very satisfied) but do not provide equal intervals between the levels of satisfaction. Therefore, it does not qualify as an interval variable.
C) Room temperature (in Fahrenheit) in a study about stress
Room temperature in Fahrenheit represents an interval variable because it allows for meaningful comparisons and calculations. The difference between temperatures is consistent, making it possible to quantify changes in temperature and relate them to levels of stress.
D) Weight of a product in a study about perceived quality
Weight is a ratio variable rather than an interval variable. While it has meaningful differences, it includes a true zero point (absence of weight), which differentiates it from interval variables that do not have a natural zero.
Conclusion
Room temperature measured in Fahrenheit is definitively an interval variable due to its consistent scale, which allows for meaningful differences between values. Other options fail to represent interval variables either because they are nominal or ordinal, or they belong to different measurement scales, thus not satisfying the criteria for interval measurement.