What questions would you ask to find out more about the quality of the data? Why is it important to gather and report valid and reliable data?

A company that sells tea and coffee claims that drinking two cups of green tea daily has been shown to increase mood and well-being. This claim is based on surveys asking customers to rate their mood on a scale of 1–10 after days they drink/do not drink different types of tea. Based on this information, answer the following questions:
How would we know if this data is valid and reliable?
What questions would you ask to find out more about the quality of the data?
Why is it important to gather and report valid and reliable data?
4. Identify two examples of real-world problems that you have observed in your personal, academic, or professional life that could benefit from data driven solutions. Explain how you would use data/statistics and the steps you would take to analyze each problem. You may also choose topics below to help support your response:
Productivity at work.
Financial decisions and budgeting.
Health and nutrition.
Political campaigns.
Quality testing in products.