What is the mean, median, interquartile range, and standard deviation of 20, 20, 28, 28, 30, 30, 30, 36, 36, 40, 40

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

What is the equation of a line passing through the point (6,1) and parallel to the line whose equation 3x=2y+4

What are the solutions of the system? solve by graphing. y = -x^2 -6x - 7 y = 2