1. Check it out! 1 4.2.4: Fitting Linear Functions to Data

2. The data table to the right shows temperatures in degrees Fahrenheit taken at 7:00 A. M. and noon on 8 different days throughout the year in a small town in Siberia. Use the table to complete problems 1 and 2. Then use your knowledge of equations to answer the remaining questions. 2 4.2.4: Fitting Linear Functions to Data 7:00 A. M.Noon 0–3 1–1 21 57 711 1017 1629 2037

3. 1.Plot the points on a scatter plot. 2.Describe the shape of the points. 3.If x = the number of students in class and y = the number of index cards a teacher needs to purchase if every students needs 8, and she wants a couple of extra cards, what is the slope of the line with the equation y = 8x + 2 that models this scenario? 4.What is the graph of the equation y = –x + 1? 3 4.2.4: Fitting Linear Functions to Data

4. 1.Plot the points on a scatter plot. Plot each point in the form (x, y). 4 4.2.4: Fitting Linear Functions to Data

5. 2.Describe the shape of the points. The points appear to be on a straight line. The points are linear. 5 4.2.4: Fitting Linear Functions to Data

6. 3.If x = the number of students in class and y = the number of index cards a teacher needs to purchase if every students needs 8, and she wants a couple of extra cards, what is the slope of the line with the equation y = 8x + 2 that models this scenario? For a line in the form y = mx + b, m is the slope and b is the y-intercept. The slope of the line is 8. 6 4.2.4: Fitting Linear Functions to Data

7. 4.What is the graph of the equation y = –x + 1? The equation is in the form y = mx + b, so the graph will be a line. To graph a line, find two points on the line. Evaluate the function at two values of x. Easy values of x to use are 0 and 1. y = –(0) + 1 = 1 Substitute 0 for x. y = –(1) + 1 = 0 Substitute 1 for x. Two points on the line are (0, 1) and (1, 0). 7 4.2.4: Fitting Linear Functions to Data

8. Graph the two points and draw a line through them. 8 4.2.4: Fitting Linear Functions to Data