Chapter 1 DA

Nominal and ordinal scales are commonly referred as

• metric scales

• non-metric scales

• interval scales

• ratio scales

Age (in years) of a person is a variable in a:

• non-metric scale

• ordinal scale

• interval scale

• ratio scale

If we want to represent a variable with four categories using dummy variables, we need ...

• four dummies

• three dummies

• two dummies

The mean of a mean-corrected variable is 1.

• True

• False

The variance of a standardized variable is 1

• True

• False

If covariance is positive then...

• The relation between X and Y is more-more (less-less)

• The relation between X and Y is more-less (less-more)

The correlation measures the direction (sign) and strength of the linear relationship between 2 variables

• True

• False

The covariance of a standardized variable is ...

• equal to the correlation

• always equal to 1

• equal to the covariance of the original variable