Wednesday (11/14) = Matching Vocab and AP MC Test!
- Vocab List:
- Explanatory Variable
- Response Variable
- Scatterplot
- Correlation
- Positive Association
- Negative Association
- Lurking Variable
- Actual Value (y)
- Predicted Value (y-hat)
- Least Squares Regression Line (LSRL)
- Slope
- Y Intercept
- Coefficient of Determination (R^2)
- Residual Plot (what is it? what is it used for?)
- Residual (formula)
- Residual (what is it?)
- Residual (what does it look like on a graph?)
- Overestimate
- Underestimate
- Outlier
- Leverage
- Influential Point
- Extrapolatino
- Interpolation
- Re-express data
- Multiple Choice Concepts (these overlap with Thursday's test)
- Interpret slope
- Interpret y-intercept
- Interpret R^2
- Know how a point influences correlation, slope, y-int (like Thursday's HW)
- Use a re-expressed model to predict (like Monday's example/packet)
- Identify points with largest/smallest residual, most/least leverage, highest/lowest x or y-value
Thursday's Test (11/15) = AP MC and AP FR!
- Concepts to know:
- How to read a computer output (write LSRL)
- Find correlation given a computer output
- How to find the LSRL, r, and R^2 with your graphing calculator
- View a scatterplot and a residual plot on your graphing calculator
- Describe an association
- Determine if a linear model is appropriate
- Interpret slope
- Interpret y-intercept
- Interpret R^2
- Use an equation to make predictions
- Calculate the residual for a prediction
- Use residuals and the equation to find an actual value
- Interpret the meaning of a residual
- Describe how a point may influence slope, intercept, and/or correlation and explain why
- Use a re-expressed model to make predictions
- Determine if a prediction would be too large, too small, or accurate given a residual plot
Grading Criteria: AP Free Response Groupwork
- 2007 (Form B) Problem (Heights of Fathers and Daughters)
- Section 1: Graphical Portion
- To get essentially correct the line had to be correctly drawn AND the residual is correctly drawn
- One of these two components = P
- Section 2: Calculation of Residual
- Essentially correct = correct residual with work shown
- Partially correct = correct magnitude of the residual but incorrect sign (should be negative)
- Incorrect = incorrect residual or no work shown
- Section 3: Effect on slope
- Essentially correct: student states the slope will remain about the same (or decrease very slightly) and explains based on the new point fitting the original pattern or falling close to the LSRL (low residual)
- *If student says "slope decreases" this is incorrect
- Partially correct: student states slope will remain about the same but explanation is weak/unclear
- Section 4: Effect on correlation
- Essentially correct: states new correlation will increase and explains based on the new point fitting the original pattern AND having high leverage
- Partially correct: correlation increases with an explanation that is...
- "Point is close to the line/low residual"
- Or has one of the two (point fits original pattern, has high leverage)
- For each section E = +1 point, P = +0.5 points
- 2012 Problem (Sewing Machines)
- Part A:
- Essentially correct: student correctly describes shape (curved), direction (positive), strength (weak/moderately weak/somewhat weak), and does so in context
- Partially correct: student does 3 of the 4 things listed for E
- Part B:
- Essentially correct: correct estimation of the point (2200, 65) AND explains that the shape of the scatterplot is curved with this point (and would appear roughly linear without it)
- Partially correct: correct value of point and explanation =....
- point is an outlier
- removal of the point makes pattern more linear
- point does not follow the pattern of the others
- "High residual, high leverage"
- Part C:
- Essentially correct = circles the 2 correct points
- Partially correct = correct two points AND one ore two additional points are circled, OR one of two correct points is circled and at most one additional point is circled
Tomorrow I will post all ofthe answers to the review packet provided today (a great tool to study), but here are the first page--you definitely need to know stuff like this for tomorrow:
- 4.) A response variable.... C
- 3.) It's easy to measure... A
- The model sqrt(distance)... A
- For the model y = 1.9... E
Want some more practice? Try these problems in the book (and check your answers)
- Page 245: 1, 11abcd, 17, 27
- Check your answers in the back of the book! (under Part II Review)
No comments:
Post a Comment