Warm Up 1. Please have your homework and tracking sheet out and ready for me when I get to you. a. Find the line of best fit for these data. _______________________ b. What is the correlation coefficient for these data to the nearest hundredth?______________________ c. Based on these data what might the number of twins’ births be expected to be in 1997? d. Actually in 1997, there were 104,137 sets of twins born. What does this mean about the line of best fit? What might explain this discrepancy?
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Warm Up 1. Please have your homework and tracking sheet out and ready for me when I get to you. a. Find the line of best fit for these data. _______________________.
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Warm Up
1. Please have your homework and tracking sheet out and ready for me when I get to you.
a. Find the line of best fit for these data. _______________________ b. What is the correlation coefficient for these data to the nearest
hundredth?______________________ c. Based on these data what might the number of twins’ births
be expected to be in 1997? d. Actually in 1997, there were 104,137 sets of twins born.
What does this mean about the line of best fit? What might explain this discrepancy?
Homework Answers
Next Week
Review Monday Test Tuesday I WILL be available for make up and
tutoring after school on Monday since the test is on Tuesday.
Review 2:
List the intervals where theGraph is increasing.
List the intervals where theGraph is decreasing.
What is the limit as “x” Approaches infinity?
What is the limit as “x”Approaches -infinity?
You Do
16
(1, 18) List the intervals where theGraph is increasing.
List the intervals where theGraph is decreasing.
What is the limit as “x” Approaches infinity?
What is the limit as “x”Approaches -infinity?
Standard Form Vertex Form
What is the vertex form of y = 2x2 + 10x + 7 ?
You may either complete the square or use your calculator.
You Do
Write the function in vertex form.
y = x2 – 4x + 6
Quick Check1. In your own words, define vertex, zeroesand
axis of symmetry of a parabola.
2. Find the vertex and zeros of y = 3x2 – 4x – 2
Quadratic Regression
What is the difference between a quadratic function and a quadratic regression?
QuadReg 1. STAT: edit. 2. Enter the values of the _____________ variable in L1. 3. Enter the values of the _____________ variable in L2. 4. Make sure your calculator is set to_______________ so that
you can observe the ______________ _____________, and determine how good a fit your model is.
5. 2nd: Y= 6. Turn on the first STAT Plot 7. STAT CALC 8. QuadReg (number ____).
R2
Instead of an r value, quadratic regressions have an r2.R2tells us :
What percentage of the time the model will be a good fit for the data.
Cigarette Consumption a. Create the
scatterplot for this data. Notice how the plot seems to __________ rapidly and then ________ _______ before cigarette consumption begins to fall off.
b. What is the quadratic regression for this data?
c. What is the r2 value? How good a model is this?
US Cigarette consumption
Cont….
d. When did consumption from the most rapidly? What events in history might account for this steep increase?
e. When does the consumption drop? Why?
Quadratic vs. Linear Regression
I use LINEAR when my y-values seem to consistently INCREASE OR DECREASE
I use QUADRATIC when my y-values seem to INCREASE AND THEN DECREASE (or vice versa)
The Chesapeake Bay
Average Monthly Temperatures of the Chesapeake Bay
Month
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Temp 31 34 44 54 64 72 76 75 68 57 47 36
a. What is the independent variable? b. What is the dependent variable? c. Enter your data in L1 and L2. Look at the scatterplot.d. Talk with the person sitting next to you about what the window should be: