You are asked to help decide which of the following issues can be solved by conducting a regression analysis.

From the list below identify the issues that can be addressed with regression analysis (including the linear probability model).

1. Predict whether a customer will churn in the future.
2. Segment the market based on the income and agesimultaneously.
3. Calculate the average grocery spending of Australian households.
4. Investigate how advertising affects firm's sales.
5. Investigate the effect of service quality on customers' satisfaction.
6. Explore how price promotion affects firm's profit.