Why is picking a cencus better than picking a sample when conducting a survey

How many days was the temperature above 90 degrees?

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?  

What numbers are included in the set of integers? what numbers are not included?