The use of statistics really helps researchers to solve problems and make decisions. If you find a problem, namely the company's turnover does not reach the target, then after looking for the cause, it turns out that the company's selling price is more expensive than the average selling price of competitors. The company leadership asks you to investigate this phenomenon.

Based on the above phenomenon,

a. What statistical tools are suitable for solving the above problem?

b. Explain why you chose this statistical tool?