1. Chapter 3 Lesson 3.4 Graphical Methods for Describing Data 3.4: Displaying Bivariate Numerical Data

2. Scatterplots When to Use Bivariate numerical data How to construct - Draw a horizontal scale and mark it with appropriate values of the independent variable - Draw a vertical scale and mark it appropriate values of the dependent variable - Plot each point corresponding to the observations Scatterplots are discussed in much greater depth in Chapter 5.

3. Activity: Create a Scatterplot Plot on the scatterplot (shoe size, height)

4. Cumulative Relative Frequency Plot When to use - used to answer questions about percentiles. How to construct - Mark the boundaries of the intervals on the horizontal axis - Draw a vertical scale and mark it with relative frequency - Plot the point corresponding to the upper end of each interval with its cumulative relative frequency, including the beginning point - Connect the points.

5. The National Climatic Center has been collecting weather data for many years. The annual rainfall amounts for Albuquerque, New Mexico from 1950 to 2008 were used to create the frequency distribution below. Annual Rainfall (in inches) Relative frequency Cumulative relative frequency 4 to <50.052 5 to <60.103 6 to <70.086 7 to <80.103 8 to <90.172 9 to <100.069 10 to < 110.207 11 to <120.103 12 to <130.052 13 to <140.052 Find the cumulative relative frequency for each interval 0.052 0.155 0.241 + + Continue this pattern to complete the table

6. The National Climatic Center has been collecting weather data for many years. The annual rainfall amounts for Albuquerque, New Mexico from 1950 to 2008 were used to create the frequency distribution below. Annual Rainfall (in inches) Relative frequency Cumulative relative frequency 4 to <50.052 5 to <60.1030.155 6 to <70.0860.241 7 to <80.1030.344 8 to <90.1720.516 9 to <100.0690.585 10 to < 110.2070.792 11 to <120.1030.895 12 to <130.0520.947 13 to <140.0520.999 In the context of this problem, explain the meaning of this value. To create a cumulative relative frequency plot, graph a point for the upper value of the interval and the cumulative relative frequency Plot a point for each interval. Plot a starting point at (4,0). Connect the points.

7. Rainfall Cumulative relative frequency What proportion of years had rainfall amounts that were 9.5 inches or less? Approximately 0.55

8. Rainfall Cumulative relative frequency Approximately 30% of the years had annual rainfall less than what amount? Approximately 7.5 inches

9. Rainfall Cumulative relative frequency Which interval of rainfall amounts had a larger proportion of years – 9 to 10 inches or 10 to 11 inches? Explain The interval 10 to 11 inches, because its slope is steeper, indicating a larger proportion occurred.

10. Time Series Plots When to Use - measurements collected over time at regular intervals How to construct - Draw a horizontal scale and mark it with appropriate values of time - Draw a vertical scale and mark it appropriate values of the observed variable - Plot each point corresponding to the observations and connect To describe - comment on any trends or patterns over time Can be considered bivariate data where the y-variable is the variable measured and the x- variable is time

11. The accompanying time-series plot of movie box office totals (in millions of dollars) over 18 weeks in the summer for 2001 and 2002 appeared in USA Today (September 3, 2002). Describe any trends or patterns that you see. According to the 2001 and 2002 data, there are seasonal peaks at weeks 4, 9, and 14, and seasonal lows at weeks 2, 6, 10-12, and 18.

12. Homework Pg.138: #3.34 Pg.146: #3.39, 3.40 Bring any coloring supplies and a ruler