Dan, an office manager, wants to replace the catering company in charge of the office lunch. The new company promises the same quality of food at a smaller cost. Before he makes the switch between companies, Dan sends out a satisfaction survey of the old company to a sample of 303030 employees. After a month with the new company, he sends out the same satisfaction survey to the same group of employees. Each survey produces a satisfaction rating. Dan wants to test if the results suggest a significant difference in the average satisfaction rating between the old and the new catering companies. Assume that the necessary conditions for inference were met. Requried:
What is the most appropriate test and alternative hypothesis?