New Seats – Block 1

New Seats – Block 2

Warm-upwith Scatterplot Notes

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Student of the day!Block 1

Student of the day!Block 2

Terms for Ch. 3 1) bivariate 14) line of means2) Linearity 15) regression effect3) Trend 16) regression toward4) Strength the mean5) predicted - response variable 17) residual plot6) predictor - explanatory variable18) exponential7) lurking variable relationships8) Extrapolation 19) Power

Relationships9) Interpolation 20) power

transformations10) prediction errors11) Residuals12) method of least squares13) least squares line or regression line

3.1 Scatterplots

Before we were studying single variable data, now we arelearning about bivariate data.

Scatterplots have two variables: The predictor or explanatory variable is on the x-axis.The predicted or response variable is on the y-axis.

If you created a scatter plot comparing tests scores tohours spent studying, on which axes would you put each ofthe variables?

Some examples to look at

Describing Scatterplots

• Scatterplots can be described by their:

• Shape: linearity clusters (fans has variability vs. less variability)

outliers (in the x or in the y)

• Trend: positive or negative

• Strength: strong, weak or no correlation

Positive or Negative correlation?Identify which variable is the independent variable and which is the

dependent.1) A graph comparing the number of hours spentstudying and the grade on a test.

2) A graph showing the years after a car accident and thecorresponding car insurance rates.

3) A graph comparing shoe size and height.

Pinching Pages ActivityMaterials: Graph paper, pencil, ruler, and textbook• You will use the front cover EVERY time you pinch pages. • To be more accurate use millimeters. Align the bottompage with 0 on the ruler and the top of the cover is themeasurement you are writing down.

Activity is on pg 117.*You are creating a table of your measurements for 50, 150, 200, 250 pages. Count the pages!!! The textbookdoes not start with page 1. *When you are done measuring and putting your data in an organizedtable, create a scatter plot (label everything), and answer 4 – 7 inComplete sentences on your sheet.

Results of Pinching Pages Activity

• You should have a table displaying 50, 150, 200 and 250 pages and the thickness in mm for each.

• Your scatter plot should have a title labels and 4 dots representing your data.

4) Does the plot look linear? Should it? Discuss why or whynot, and make your measurements again if necessary. On theplot, place a straight line that best fits the cloud of points.5) Find the slope and y-intercept of your line. What does they-intercept tell you? What does the slope tell you? What isyour estimate of the thickness of a sheet?

#6 and #7 from Pinching Pages

6) Use the information in your graph to discuss howmuch your estimate in step 5 is likely to vary from thetrue thickness.

7) How would your line have changed if you hadn’tincluded the front cover?

H.W. AssignmentA.P. Statistics - 3.1 E#1 - 4 Read 3.2