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_hist

ogram.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 Now1. 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 P

eopl

e

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.