What is the standard deviation of the data set 21 ,6,18,21,20,14,19

Create a real-life situation and create a system and show how it might be modeled algebraically with a system of equations (or inequalities) show all work include a few sentences explaining the situation, your variables of choice and what each represents, and how you would set it up and solve it algebraically. !

Which of the following is an equation of a line parallel to the equation y=4x+1?

Are the corresponding angles congruent? explain why or why not.