Presentation is loading. Please wait.

Presentation is loading. Please wait.

Holt McDougal Algebra 2 1-4 Curve Fitting with Linear Models Cover 1.4 if time; non-Algebra 2 objective Gasaway going over briefly: get students to narrow.

Similar presentations


Presentation on theme: "Holt McDougal Algebra 2 1-4 Curve Fitting with Linear Models Cover 1.4 if time; non-Algebra 2 objective Gasaway going over briefly: get students to narrow."— Presentation transcript:

1 Holt McDougal Algebra Curve Fitting with Linear Models Cover 1.4 if time; non-Algebra 2 objective Gasaway going over briefly: get students to narrow down, positive verse negative correlation just by appearance and how to do on calculator Teaching note

2 Bell Ringer Find each slope: 1. (5, – 1), (0, – 3)2. (8, 5), ( – 8, 7)

3 Fit scatter plot data using linear models with and without technology. Use linear models to make predictions. 1.4 Objectives A line of best fit may also be referred to as a trend line.

4

5 Holt McDougal Algebra Curve Fitting with Linear Models FOUR KINDS OF CORRELATIONS (YOU WILL LEARN ABOUT IN TRANSITION) Positive Correlation Negative Correlation Constant Correlation No Correlation

6 Holt McDougal Algebra Curve Fitting with Linear Models **Practice how to use calculator with following slide ** make sure all steps are included for students **Need uncooked spaghetti for this unit (optional). Be patient, allow students time to copy question and data. Offer students graph paper Teaching note:

7 Holt McDougal Algebra Curve Fitting with Linear Models Scatter Plots + Calculator 1) STAT  #1  L1 (x), L2 (y) (enter data; use arrow keys to select column)  STAT  CALC  4enter LinReg(ax+b)  2 nd  8) y=  plot1  on  TYPE  X list L1 & Y list L2  mark (select on)  GRAPH

8 Example 1 Albany and Sydney are about the same distance from the equator. (a)Make a scatter plot with Albany’s temperature as the independent variable. (b)Name the type of correlation. (c)Then sketch a line of best fit and (d)find its equation. That’s to much work with paper & pencil How to: Calculator data entry continuedcontinued Enter ______ in list L1 by pressing STAT and then 1. Enter _______ in list L2 by pressing  Make scatter plot in the following way: Press 2 nd Y= PLOT 1 set up desired type when done, press GRAPH Tables: ACT

9 o o Does yours look like this ? example 1 continued Albany and Sydney are about the same distance from the equator. (a)Make a scatter plot with Albany’s temperature as the independent variable. (b)Name the type of correlation. (c)Then sketch a line of best fit and (d)find its equation. (hint: what is m? b?)

10 Example 2 (a)Make a scatter plot for this set of data. (b)Identify the correlation (c)sketch a line of best fit (d)find its equation.

11 Holt McDougal Algebra Curve Fitting with Linear Models Teaching note: following slide Do not advance to next slide until students have had time to finish previous slide

12 Step 1 Plot the data points. Step 2 Identify the correlation. Notice that the data set is positively correlated–as time increases, more points are scored example 2 continued

13 Step 3 Sketch a line of best fit. Draw a line that splits the data evenly above and below. example 2 continued Step 4 Identify the equation for the data. end

14 Example 3: Anthropology Application Anthropologists can use the femur, or thighbone, to estimate the height of a human being. The table shows the results of a randomly selected sample. (a)Make a scatter plot for this set of data. (b)Identify the correlation (c)sketch a line of best fit (d)find its equation.

15 a. Make a scatter plot of the data with femur length as the independent variable. example 3 continued

16 Holt McDougal Algebra Curve Fitting with Linear Models b. Find the correlation coefficient r and the line of best fit. Interpret the slope of the line of best fit in the context of the problem. Enter the data into lists L1 and L2 on a graphing calculator. Use the linear regression feature by pressing STAT, choosing CALC, and selecting 4:LinReg. The equation of the line of best fit is h ≈ 2.91l Example 3 Continued

17 Holt McDougal Algebra Curve Fitting with Linear Models Example 3 Continued What does the slope indicate about problem?

18 c. A man’s femur is 41 cm long. Predict the man’s height. Substitute 41 for l. The height of a man with a 41-cm-long femur would be about 173 cm. h ≈ 2.91(41) The equation of the line of best fit is h ≈ 2.91l Use the equation to predict the man’s height. For a 41-cm-long femur, h ≈ Example 3 Continued end

19 Example 4 a. Make a scatter plot of the data with horsepower as the independent variable. The gas mileage for randomly selected cars based upon engine horsepower is given in the table.

20 Holt McDougal Algebra Curve Fitting with Linear Models b. Find the correlation coefficient r and the line of best fit. Interpret the slope of the line of best fit in the context of the problem. Enter the data into lists L1 and L2 on a graphing calculator. Use the linear regression feature by pressing STAT, choosing CALC, and selecting 4:LinReg. The equation of the line of best fit is y ≈ –0.15x Example 4 Continued

21 c. Predict the gas mileage for a 210-horsepower engine. Substitute 210 for x. The mileage for a 210-horsepower engine would be about 16.0 mi/gal. y ≈ –0.15(210) The equation of the line of best fit is y ≈ –0.15x Use the equation to predict the gas mileage. For a 210-horsepower engine, y ≈ 16 Example 4 Continued The slope is about –0.15, so for each 1 unit increase in horsepower, gas mileage drops ≈ 0.15 mi/gal. What does the slope indicate ? end

22 Holt McDougal Algebra Curve Fitting with Linear Models Teaching note: Exit Question long

23 Exit Question: complete on graph paper attached to Exit Question sheet (a)Make a scatter plot for this set of data using your calculator (b)find its equation.


Download ppt "Holt McDougal Algebra 2 1-4 Curve Fitting with Linear Models Cover 1.4 if time; non-Algebra 2 objective Gasaway going over briefly: get students to narrow."

Similar presentations


Ads by Google