Final answer:
A measurement with a true zero point, such as income, should be measured using the ratio scale level. This scale allows for the construction of ratios because it has a true zero, which indicates the absence of the quantity being measured.
Step-by-step explanation:
A measurement with a true zero point, such as income, should be measured using the ratio scale level of measurement. The ratio scale is the highest level of measurement, which contains all the properties of an interval scale, along with a true zero point, making it possible to construct a meaningful ratio.For example, if two people have incomes of $0 and $50,000 respectively, the one with $50,000 has an infinite amount more income than the one with $0, because income has a true zero point where no income exists. Unlike income, some scales like temperature in Celsius or Fahrenheit do not have a true zero and are measured using the interval scale since 0 degrees does not mean 'no temperature'.In summary, when a dataset includes a true zero point, allowing for the calculation of ratios, it should be measured using a ratio scale. This is essential for conducting correct statistical procedures and accurate analysis.