Find the constant of proportionality for the table of values

The given dot plot represents the average daily temperatures, in degrees fahrenheit, recorded in a town during the first 15 days of september. if the dot plot is converted to a box plot, the first quartile would be drawn at __ , and the third quartile would be drawn at __ link to graph: .

Ineed me i stuck and i don’t want to get it wrong

What are the solutions of the system? solve by graphing. y = -x^2 - 3x + 2 y = -2x + 2