Describe and classify this database and its parts:
a.* Is this a univariate, bivariate, or multivariate data set?
b. What are the elementary units?
c. Which variables are qualitative and which are quantitative?
d.* Is “training level” ordinal or nominal? Why?
e. Would you ever want to do arithmetic on “employee number”? What does this tell you about whether this is truly a quantitative variable?
f. Is this a time series, or are these cross-sectional data?