A statistics student has collected data from a random sample of 20 college students at his school. He collected data on many variables including GPA (grade point average) and how many hours per week they play video games. He uses his calculator to find the equation of the line of best fit and uses it predict the GPA of college student who plays 30 hours of video games per week. What are two things we should check to determine whether making this prediction is valid/ reasonable?