How do you do this? this is sort of confusing me

Which of the following is true for the relation f(x)=2x^2+1

Aschool puts on a play. the play costs $1,200 in expenses. the students charge $4.00 for tickets. there will be one performance of the play in an auditorium that seats 500 people. what is the domain of the function that shows the profit as a function of the number of tickets sold?  

Standard deviation of 19,29,21,22,23