In Exercises 21-28,determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate.

Fast Food Service Times In a study of fast food service times, a researcher records the time intervals of drive-up customers beginning when they place their order and ending when they receive their order.

Fast food service times are recorded in the form of time intervals for drive-up customers

Data values are measured on a scale depending on their type and amount of precision required. Two of the four levels of measurements are explained below:

Interval level of measurement: It is used to code numerical data that can be subtracted and holds countable/measurable values. For example, the pH level of a chemical ranges from 0 to 14. A zero-pH value does not mean zero acidic levels. Also, the difference between the pH levels 3.4 and 4.4 is the same as the difference between the pH levels 7.2 and 8.2.

Ratio level of measurement: It is also used to code numerical data where the distance between the values is measurable. The ratios can be determined, and the natural zero starting point is well-defined. For example, the length of a dress is measured in inches. A 60-inch dress is twice as long as a 30-inch dress. A zero-inch length indicates no measurement.

As time intervals can be measured in minutes and a true zero value of the time interval of service indicates no service granted; thus, the time interval for a fast foodservice can be measured on a ratio scale.