Hypothesis testing for difference between two means.

1. Sum up a business problem and describe both the sampling technique and the sample size that you would require to set up a research project to solve this problem.

2. A situation occurs at your company where you are trying out a new procedure improvement for invoice processing. Data are collected for a week before the implementation and it takes the department 5.3 hours to process the invoice with a sd of 7.6. Afterwards, the department can process the invoice in 4.7 hours with a sd of 8.3. The project manager declares this test a success and wants to implement this new process in the rest of the company. After doing a t-test, you do not find significance, as there is too much variability in the data both before and after. What would you do in this situation?

3. describe a business situation that you have had or might face that will benefit from the use of confidence intervals?