1. 2.4 Using Linear Models

2. Slope is “rate of change” Examples: Look for KEY words! 23 miles per gallon 20 gallons/second 3 inches each year $3 a ticket

3. Problem Type 1: A rate is given A balloon is released from the roof (at 30 feet above ground). The balloon rises at a rate of 12 feet per second. Write an equation to model the balloon’s height h after t seconds.

4. Problem Type 2: No rate is given, find it from points. (Identify the independent and dependent values) There were 174 words typed in 3 minutes, 348 words typed in 6 minutes. How many words will be typed in 8 minutes? Hint: Usually time is the x-value.

5. 2.4 Using Linear Models HW: Page 81 #1-8 all, 16, 19

6. Warm-up Activity Lab p. 86

7. Scatter Plots Graphs that relate two different sets of data by plotting the data as ordered pairs. Used to determine the relationship between data sets (for example, x and y values). Trend line: a line that approximates the relationship between the data sets of a scatter plot. Used to make predictions.

8. Scatter Plots Ex 3) A student is considering buying a 1999 car for $4200. She researches prices for various years of the same model and records the data in a table. a.Let x represent the model year and y be the price. Draw a scatter plot. Decide whether a linear model is reasonable. b.Use your graphing calculator to find a trend line for the data. Determine whether the asking price is reasonable.

9. 2.4 Using Linear Models Page 81 # 13, 19, 21