A researcher wants to conduct a before/after study on 5 shops to determine if a radio advertising results in any difference in sales (in thousands of dollars). The following data are collected.

Shop No.	1	2	3	4	5
Before	35	46	23	41	15
After	48	45	29	43	32

Required:

(1) Formulate the null and alternative hypotheses for the test. Clearly define population parameters. (2 marks)

(2) Conduct a hypotheses test at 10% significant level to determine whether there is any difference in sales for these 5 shops. (5 ma