The American Association of Port Authorities randomly audits the top 100 seaports (by tonnage). To determine which of the top 100 seaports to audit, they first group the seaports by region and then randomly selects seaports from each grouping. What kind of sample is this? Cluster Sample Simple Random Sample Stratified Sample Systematic Sample Restaurants are rated based on their cleanliness by local governments. They often use a 12-point scale A, A-, B+, B, B-, C+, C, C-, D+, D, D-, and F. Use this scale for questions 12 & 13. What level of measurement does this scale use? O O Ratio O Interval Nominal Ordinal