Answer/Explanation:
There are basically 4 main levels of measurement or scales of measurement. They are:
1. Nominal scale: this deals with variables that are categorised, and numbers o i.e.r alphabets assigned are just for the sake of naming, and as such has no numeric value.
2. Ordinal scale: this scale is only used to show order or ranking if variables.
3. Interval scale: in this type of scale, numbers that are ordered have meaningful divisions.
4. Ratio scale: this can be like to interval scale, in that, the ordered numbers have meanings. However, unlike the interval scale, when zero is used, meaningful deductions can be made as zero is meaningful.
Therefore, level of measurement for the variables given in the question are as follows:
a. Distance students travel to class: ratio scale. I.e. zero in this scale is meaningful and would mean no distance was travelled
b. A classification of students by the state of birth: nominal scale, i.e. this only serves the purpose of categorization. The scale here has no numeric value,
c. A classification of students by ethnicity: nominal scale
d. A classification of workers by industry: nominal scale
e. Selling price of the Statistics textbook: ratio scale
f. Student IQ ratings: interval scale, i.e., zero in this scale is not meaningful.
