1. Writing About Math Complete 1-5 Silently
Homework: Maintenance Sheet #21 (1-6)

2. MCC8.SP.1 , MCC8.SP.2 , MCC8.SP.3 , MCC8.SP.4
I can describe the relationships shown in a scatter-plot (identifying patterns such as I can describe a relationship as increasing or decreasing, linear or nonlinear, from an equation, table or graph.
I can construct and interpret scatter plots. clustering, outliers, positive or negative association, linear association, and nonlinear association).
I can sketch a line of best fit on a scatter plot
I can justify the location of my line of best fit and explain why or why not a given line is a good fit.

3. Which scatter plot shows the same data?
Sabrina is planning a surprise birthday party for her sister. She collected information for the cost from different venues and different numbers of guests at the party. The table below shows the information she collected.
Number of Guests
Cost of Party ($)
Which scatter plot shows the same data?

4. What/ Why Scatterplots?
Scatter plots are used to examine two sets of data and to investigate the possible relationship between two quantities. A trend line, or line of best fit, allows predictions to be made based on current data

5. Example:
Ms. James asked each of her students how many hours they studied for the big unit test.
The scatter plot shows the number of hours the students studied, and the grades they earned on the test.
Write a statement that describes the relationship between the hours spent studying and the grade earned on the test?

7. Solution:
Using the line of best fit, a prediction can be made about the data. Two identifiable points that are on the line of best fit are (0, 40) and (3, 60). Subtract the coordinates of the left point from the coordinates of the right point.
Number of Hours Studying: 3 hours - 0 hours = 3 hours
Grade: 60 points - 40 points = 20 points
Therefore, the relationship is for every 3 hours the students studied, the grade earned on the test went up by 20 points.

8. Line of Best Fit Video 1 Video 2
*Some scatter plots display data points which appear to trend toward a linear relationship, but do not form a straight line. *A linear relationship can be approximated relative to that data by using a line of best fit. *A line of best fit is a line which best represents the data. *A line of best fit can be used to analyze the data in several ways, including investigating a correlation between variables and making predictions outside the displayed data.

9. Which of the scatter plots below shows the most accurate line of best fit?x y z

10. Work Session/ Independent Practice
I can describe the relationships shown in a scatter-plot (identifying patterns such as I can describe a relationship as increasing or decreasing, linear or nonlinear, from an equation, table or graph.
I can construct and interpret scatter plots. clustering, outliers, positive or negative association, linear association, and nonlinear association).
I can sketch a line of best fit on a scatter plot
I can justify the location of my line of best fit and explain why or why not a given line is a good fit.
Work Session/ Independent Practice

11. A line of best fit can be used to interpret a set of a data and make predictions within (interpolate) and outside of (extrapolate) the set of data.
The graph below shows a line of best fit for data collected on the cost of miniature golf in relation to the number of players
Determine what the slope and the y-intercept of the line of best fit represent.
The equation of the line of best fit for the graph is y = 2x + 4.
The slope represents the cost per player, which is $2.00.
y-intercept is an initial fee at the miniature golf course, which is $4.00.