1.A leading airline is planning to conduct its annual customer satisfaction study among its customers. The airline has decided to use its customer database of past two years as the sampling frame. The airline uses the study findings to improve customer services in the following areas: Airport interactions (Check-in, boarding, baggage handling on arrival), In-flight services (Quality and Variety of Food, cleanliness), and flight operations (On-time performance, connectivity between cities, timing of flights). The studies conducted in the previous years indicate that there is a substantial variation in the satisfaction scores between frequent fliers, and non-frequent fliers. Also, there are large differences in satisfaction scores provided by customers to different airport operations.

The proposed study should provide adequate insights to develop plans for all the areas mentioned above. A total sample size of 10,000 was decided upon.

a)List two sampling methods that are appropriate for this study?

b)Which specific method of sampling would you recommend to the airlines for this survey? Why?

c)What other information from the previous years' study would be useful to you in fine-tuning your sampling design, and sample sizes?