Chapter 2 Organizing Data

Section 2.1

Frequency Distributions, Histograms, and Related

Topics

Do Now

• Using the chart on the board, place a tally mark in two spots:– The number of letters in your first name– The number of letters in your last name– Ex: My first name is Mark, so I’d put a

tally mark at “4”. My last name is Frew, so I’d put an additional tally mark at “4”.

Histograms (Example)

• http://www.cyber-wit.com/gallery_histogram.html#histogram

Copy Figure 2-8 into Notebook

• Mound-shaped Symmetrical• Typical Uniform• Skewed Left• Skewed Right• Bimodal

Basic Steps for Creation by Hand

• Determine the Number of Classes• Determine Class Width• Determine Class Boundaries• Tally• Find Relative Frequencies• Find Midpoints• Graph (X axis = # Line, Y Axis = Freq

or Rel. Freq)

Do Now

• Using the NFL Touchdown Data from 2011, complete the frequency distribution.

Steps in Excel:

• Be sure Data Analysis Toolpack is installed• To Let Excel Decide on Bins:– Choose Data, Data Analysis, Histogram– Input Range is your data range.– Click Label if you have a title for your data.– Click Chart Output.– To make bars touch, click into white space on

histogram:choose chart tools, design, chart layout #8

– Be sure to fix titles and labels

Steps in Excel:

• To have User Defined Bins:–Next to your data, type the right

endpoint of each of your bars, with the exception of the last bar.

– Choose Data, Data Analysis, Histogram– Input Range is your data range.– Bin Range is your right endpoints.– Click Label if you have a title for your

data.– Click Chart Output.

Do Now:

1. Display Homework2. Download Weekly Hershey Stock

Prices from my Wikisite and create a histogram of the prices.

Do Now

• Display your homework• Download Class of 2012 Math PSAT

scores from my wikisite

Do Now

• Download NFL Touchdowns for Histograms– Using number of touchdowns:

1. Create a histogram of bin width 102. Create another histogram having 8 bins

Quiz Directions

• Download Eagles Roster from wikisite– Using the weights:1. Create a histogram with 6 bins2. Create a histogram with bin width of

30 (starting at minimum weight).

Do Now

• Click on the link “USA Today Snapshots” from my wikisite.

• Click through the four tabs (News, Sports, Money, and Life)

• Find one bar graph of interest and one pie chart of interest. Record at least two interesting facts from each (for a total of 4).

Bar Graphs and Circle Graphs

• Both show qualitative data.• Pie Charts are only used when you

are representing “parts of a whole” and when selections are made in only one category.

• Paretto Charts are Bar Graphs organized from greatest to least.

Now:

• Download the Eagles Roster (again) from my wikisite. Which variables are qualitative?

Do Now

• Copy important information from the blue box on page 59 into your notebook.

• Display Homework (attempted pie graph of Eagles Positions)

Practice

• Page 60 #1, 5, 8

Do Now

1. Download 100 meter dash data set from wiki.

2. Compare your homework with mine.– Titles?– Labels?

Survived Died Survived DiedFemale Male

Gender

0

100

200

300

400

500

600

700

Titanic Disaster

Third ClassSecond ClassFirst Class

Num

ber

of

People

Quiz (download 2-2 quiz data)

• Using “Phillies Winning Percentage”:– Create an adequately labeled graph that best

represents the data.

• Using “Buying Music Online” data set:– Choose an adequately labeled Paretto or Pie

graph to display the data. (You will need to choose the correct option.)

• Transfer both graphs to Word and display on one page.