6.6 Misleading Graphs (p.146-147)

This unit is practice for determining how conclusions about data can be influenced.

I.Pay attention to the question being asked in a survey:
-Does the question give preference to something (bias)?
-Do the words used influence the person being surveyed?

II.Examine graphs:
-Check the scale to see if it's been stretched or cut off?
-Is the scale consistent or does it change?

6.4-5 Box-and-Whisker Graphs (p.144-145)

I. Box-and-whisker graph
-Show how far apart and HOW EVENLY data are distributed

II. Parts of a box-and-whisker graph: 5 marks seperating data into 4 parts
A. Lower Extreme - the least value in the set of data - the point at the bottom whisker
B. Upper Extreme - the greatest value - the point at the top whisker
C. Median - find the median of the data - this is the middle line of the box
D. Lower quartile - the middle number between the median and the lower extreme - one side of the box
E. Upper quartile - the middle number between the median and the upper extreme - the other side of the box


Harcourt math site for a tool to make Box-and-Whisker Graphs

6.3 Stem-and-Leaf Plots & Histograms (p.140-142)

I.Stem-and-leaf plots
A. Stem is the first or more digits
B. Leaves show the ones digits

II.Histograms
A. Histograms show frequency in data bars for a range of intervals.
B. They are similar to bar graphs but there is no space between the bars.

Check out this link from Purplemath for a more in depth explaination of stem-and-leaf plots.

6.2 Make & Analyze Graphs (p.136-139)

I. Graphs are tools for visually comparing.
II. Pay attention to the following items when analyzing graphs
A. Title: It should cleary explain how to look at the data
B. Lables: describe the variables for both axis
C. Key: the tool that explains symbols
D. Scale: this can drastically change how values are represented