# Levels of Measurement: Interval/Ratio

Understand the levels of measurement.

## Exponents: Definition and Practice Questions

Interval/ordinal measurements provide the most information about any variable. For interval/ratio level variables not only can you order the values of the cases but you know the distance among each of the cases. While in ordinal level variables we know the position of each case compared to each other, it is only with interval/ratio level we know how far apart each case value is to one another.

Other Examples of Interval/Ratio Variable:

• Country GDP - \$2.35T; \$6.42T; \$675B; \$1.43T
• Prison Sentences – Six months; three years; 36 months; 120 days
• Approval ratings – 32%; 67%; 51%; 92%
• Gini coefficients – 0.21; 0.47; 0.12; 0.33

Why do we need to learn this? Interval/Ratio variables give us the most amount of precision and information to work with. With that greater precision and information, you have more freedom when it comes to statistical analysis.

#### What might be confusing about Interval/Ratio Variables?

There is a difference between variables measured at the interval and ratio levels. For our research purposes, this difference is meaningless, so for our class we will not emphasize the difference. For those who wish to know, the difference between the two is a variable measured at the ration level has all the attributes of an interval level measure as well as having a 'true' zero where the bottom of the measurement means the absence of that variable.

#### Can you try it on your own?

1. A marketing class of 50 students reported their address and zip code to the instructor.  The descriptive summary showed the following survey results:  2% 14201, 8% 14301, 45% 14222, 45% 14213, and 0% 14325. What scale/level of measurement are the zip code(s) reported considered?

A: Nominal

B: Ordinal

C: Interval/Ratio

D: No conclusions can be made

2. The incomes of a group of 50 loan applicants are obtained. Which level of measurement is income?

A: Nominal

B: Ordinal

C: Interval/Ratio

D: No conclusions can be made

1. A. Nominal

2. C. Interval/Ratio

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