Question $1$: "A researcher is studying the effect of covid$-19$ epidemic on small businesses in Saudi Arabia. It was found that $43\%$ of the business closed as a result of the financial challenges and health concerns. A sample of $650$ small businesses in different cities have filled a questionnaire, some of the questions were as: Have you been diagnosed with COVID$-19?$ Amount of Demand in thousands? Number of employee diagnosed?"

Using the above statistical experiment, Fill the following blanks:

a$.$ Population:

b$.$ Experiential

c$.$ Sample :

What are the variables in the experience? Specify the kind of each one?