4.Researchers used the following item to measure registered nurses' (RNs) income in a study:

What category identifies your current income as an RN?

a.Less than $50,000

b.$50,000 to 59,999

c.$60,000 to 69,999

d.$70,000 to 80,000

e.$80,000 or greater

What level of measurement is this income variable? Does the income variable follow the rules outlined in Figure 1-1? Provide a rationale for your answer.

Figure 1-1 shows:

Nominal: Exhaustive categories, exclusive categories

Ordinal: Exhaustive categories, exclusive categories, ranked categories

Interval: Exhaustive categories, exclusive categories, ranked categories, equal interval categories

Ratio: Exhaustive categories, exclusive categories, ranked categories, equal interval categories, absolute zero categories