What is an example of a number that is not real

Shiny white dental insurance costs $258 per year. approximately one-third of insured people need a filling, which averages $110 each. 80% of insured people get a preventive check-up each year, and the average cost of this visit is $95. if you consider shiny white’s income and expenses, what is the expected value of each insured customer?

Evaluate 4 a for a = 5 2/3 . express your answer in simplest form.

What is the surface area of the sphere?