Algebra 1

1
Algebra 1

• Ch 1.6 Tables Graphs

2
Objective

• Students will use tables to organize data and
  create bar circle graphs

3
Data

• The word data means information, facts or numbers
  that describe something
• A collection of data is easier to understand when
  the data are organized in a table or graph.
• There is no best way to organize data...Often it
  helps to put numbers in increasing or decreasing
  order or group numbers so that patterns and
  trends are more apparent

4
Creating a Table

• It is relatively simple to create a table..
• First, collect the data
• Then create the table and organize the data into
  a format that will communicate what you found out
  about the data
• The minimum requirements for any table are
• A Title
• Data Labels
• Actual Data

5
Example 1
Data Labels
Title
This data table is organized by company and year
6
Bar Graphs

• Often times you will be asked to create and/or
  interpret a bar graph
• Of course we are looking for higher order
  thinking skills here
• At first glance, bar graphs look nice and
  organized However, the expectation is that it is
  your job as the viewer and interpreter of the
  data to make sure that the person who created the
  bar graph is not trying to mislead you

7
Components of a Bar Graph

• All bar graphs must have the following
  information
• Title
• Data labels
• Appropriate scale
• If you create the bar graph you get to choose the
  scale
• The scale should always start at zero
• The scale should be in equal increments
• Bars
• They can go horizontally or vertically
• The bars should have a space between them
• The bars should be the same width

8
Example 2
Title
Scale starting at zero and in equal increments
Bars each bar has the same width with space
between each bar
Data Labels
9
Circle Graphs

• A circle graph is also known as a pie chart
• A pie chart never displays raw data!
• Each piece of the pie represents a percent of the
  whole
• Before we look at creating a pie chartlets talk
  about pie pieces

10
Pie Pieces

• First and foremost one of the biggest issues that
  I have come across with circle graphs is that
  students pie pieces dont represent accurate
  percentages
• While I do not require you to be 100 accurate
  with your pie pieces they should be a good
  representation of the percentage
• Lets look at some examples

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Pie Pieces 50

• If you draw a circle and cut it into 2 each piece
  will represent 50

50
50
12
Pie Pieces 25

• If you draw a circle and cut it into 4 each piece
  represent 25

25
25
25
25
13
Acceptable Representations

• The next couple of slide will demonstrate
  acceptable percentages when constructing a pie
  chart
• Again, while I do not require you to be 100
  accurateyour pie pieces should be an accurate
  representation of the data
• Use the previous 2 slides as a guide to estimate
  percentages

14
Examples

• Acceptable Not Acceptable

25
30
15
Examples

• Acceptable Not Acceptable

50
48
16
Components of a Circle Graph

• All graphs must have a title describing what the
  data represents
• In a circle graph each pie piece is labeled with
  the category and percent
• Circle graphs are usually colorful
• Againa circle graph never displays raw data!
• If you are given data as percentages you can
  create the pie chart from the percentages
• If you are given data as numbers you must convert
  the numbers into percents BEFORE you construct
  the pie chart.

17
Example Data as Percent

• Data Student Favorite Sports
• Make sure the percents add up to 100
• Construct pie chart see next slide

Sport Percent
Football 30
Basketball 25
Baseball 22
Tennis 8
Other 15
18
Student Favorite Sports
Other 15
Football 30
Tennis 8
Baseball 22
Basketball 25
19
Example Data as Numbers

• Data Types of movies in a DVD collection
• Convert each number to percent
• Create pie chart

Type of Movie Number
Action 24
Comedy 15
Science Fiction 7
20
Converting Numbers to Percent

• It is expected that you already know how to
  convert the numbers in the previous slide into
  percents
• However, as a refresher
• First you add up all the numbers an get a total.
• Then divide each number by the total and press
  the percent key on your calculator
• In this case the total is 46. Therefore
• Action represent 52.1 (24 ? 46)
• Comedy represents 32.6 (15 ? 46)
• Science Fiction represents 15.3 (7 ? 46)
• Add up all the percents and make sure they equal
  100. Its ok to round by .1

21
Types of movies in a DVD collection
Science Fiction 15.3
Action 52.1
Comedy 32.6
22
Interpreting the data

• Circle graphs provide you with a visual
  representation of the whole data set and how much
  each category represents of the whole.