National Airport Authority. The National Airport Authority (NAA) of a country stores the relevant data for all the airports in a country to perform periodic checks on their maintenance. Data from each airport are compiled into the airport inventory. Some of the variables maintained by the NAA for each airport are listed below.

Classify each variable as quantitative or qualitative.

a. Category of airport (big, medium, small)

b. Average daily traffic (number of flights)

c. Number of terminal buildings

d. Number of runways

e. Length of a runway (meters)

f. Closed at night (yes or no)

g. Condition of access road (good, fair, poor)