Write down the letter corresponding to the best answer for each question. 1.1 When the population is divided into mutually exclusive sets, and then a simple random sample is drawn from each set, this is called: [2] A. Simple random sampling. B. Stratified random sampling. C. Cluster random sampling. D. Systematic random sampling. 1.2 A marketing research firm divides the population of a state into geographic areas, and randomly selects some of the areas and takes a simple random sample of each selected area. This is an example of a [2] A. Cluster random sample B. Systematic random sample C. Simple random sample D. Stratified random sample. 1.3 Laspeyres index formula uses the weights of the. ............... [2] A. Base period. B. Current year. C. Average of the weights of a number of years. D. None of the above. 1.4 A manufacturer of contact lenses is studying the curvature of the lenses it sells. In particular, the last 500 lenses sold had an average curvature of 0.5. The population is [2] A. The 500 lenses. B. 0.5. C. The lenses sold today. D. All the lenses sold by the manufacturer