Warm-up3.4 Diagnostic of Influential Points

4)

5)

6)

Student of the day!Block 1

Student of the day!Block 2

10 minutes• Review the rubric.• Make sure you have all graphs and everything

labeled appropriately.• Make sure all questions are answered in sentences.• If your group is ready before the 10 minutes bring

up all 3 or 4 of your packets. I will use the random # generator to select one of your packets to represent the group.

A.P. Stats 3.4 Diagnostics – Looking at Influential Points

**** Plot the points on graph paper first!!

Using the original data, enter into L1 and L2.

Remove the beaver point (outlier in y)

Be sure to go back to the original data including the data forbeaverbefore removing the point for hippo.Remove the hippo point (outlier in x)

How did removing the beaver affect the data?

How did removing the hippo affect the data?

y-hat = r =

y-hat =

r =

y-hat =

r =

Scatter plot

A.P. Stats 3.4 Diagnostics – Looking at Influential Points

Using the original data, enter into L1 and L2.

Remove the beaver point (outlier in y)

Remove the hippo point (outlier in x)

How did removing the beaver affect the data?Removing the beaver data increased slope and decreased the y-intercept. The correlation coefficient increased.How did removing the hippo affect the data? Removing the hippo data changes slope and the y-intercept.

Correlation increased slightly less than removing beaver.

y-hat =10.5 + 1.58x r = 0.769

y-hat = 8.14 + 1.69x

r = 0.828

y-hat = 6.3 + 1.96x

r = 0.8

A.P. Stats – D 28 Exploration

Sit in groups of 4, where everyone has a graphing calculator.

Each person graphs a data set.Describe each graph and write the Y-hat and r.

Compare graphs, THEN calculate LineReg L1,L2, Y1

Compare the graphs with the scatterplots and the regression line drawn.

For a. which plot means which data set.

Homework 3.4 P#24, 25 and E#43

For P#24, draw a scatter plot with LSRL for c. show the residual plotP#25, do matching for a. b. and answer c.E #43, you are constructing a scatter plot with LSRL again _________________________________________Next block after 3.5 there will be a notebook check.Bring your textbook because we will begin the textbookreview next block after the 3.5 notes.***We will do an activity that will require 100 pennies or 2king sized bags of Plain M&Ms.As a table of 3 or 4, decide what you will bring and who willbring what.

Common Quiz mistakes

• Interpret the y-intercept and slope means to explain

it in context; for example for every inch the women’sheight increases the men’s height increases by 1.045.Y-intercept has no meaning in the context of women’sheight. For cereal as fat increases by one gramcalories increase by 5. A zero fat cereal has 110calories.• Show that the residuals add up to zero or show thatthe is on the LSRL. Write out residuals and showthe sum is zero or almost.

yx,