Unit 2: Organizing DataMr. Evans

Statistics

Part 1

Focus Points

• Determine types of graphs appropriate for specific data

• Construct bar graphs, pie charts, line graphs, and histograms

Bar Graphs

A Bar Graph is a graph drawn using rectangular bars to show how large each value is. 

Also known as Pareto graph, in order from greatest to least

Features

1. Display qualitative variable

2. Bars can be vertical or horizontal

3. Bars are of uniform width and uniformly spaced.

4. The length of the bars represent values of the variable being displayed. The frequency of occurrence, or the percentage of occurrence. The same measurement scale is used for the length of each bar,

5. The graph is well annotated with title, label for each bar, and vertical scale or actual value for the length of each bar.

Pie Charts

A Pie Chart is a circular chart divided into sectors, each sector shows the relative size of each value.

Also known as a Circle Chart

Features

1. Displays qualitative variables

2. The total quantity, or 100%, is represented by the entire circle. Each wedge of the circle represents a component part of the total.a) Piece of the pie

3. The proportional segments are usually labeled with corresponding percentages of the total

Guided Exercise 1

A shopping center tracks for the duration between the time of 8:00-9:00. Dillard’s sold $147, Kohl’s $279, Marshall $220, Macy’s Department $197, Nordstrom $357, and Sears sold $320.

Construct a bar and pie chart for the sales of the shopping center.

Guided Exercise 1

Dillard's Kohl's Marshall Macy's Nordstrom Sears0

50

100

150

200

250

300

350

400

Sales 8:00-9:00Store Sales

Dillard’s $147

Kohl’s $279

Marshall $220

Macy’s $197

Nordstrom

$357

Sears $320 Stores

Sale

s $

Sales 8:00-9:00

Dillard’s Kohl’s Marshall

Macy’s Nordstrom Sears

Histogram

A Histogram is a graphical display where the data is grouped into, and then plotted as bars.

Features

1. Displays quantitative variables

2. The bars have the same width and always touch

3. The height of each bar indicates frequency

Line Graphs

• A Line Graph that uses points connected by lines to show how something changed in value (as time goes by, or as something else happens).

Features

• Displays quantitative variables

• All values are connected by a line

Guided Exercise 2

1. One-Way Commuting Distances in Miles for 60 workers in Downtown Austin. Sketch a histogram.

Class LimitsClass Boundaries

Frequency

1-8 0.5-8.5 14

9-16 8.5-16.5 21

17-24 16.5-24.5 11

25-32 24.5-32.5 6

33-40 32.5-40.5 4

41-48 40.5-48.5 40.5 8.5 16.5 24.5 32.5 40.5

0

5

10

15

20

25

Commuting Distances

48.5

Distances (in miles)F

req

uen

cy

Guided Exercise 2

1. One-Way Commuting Distances in Miles for 60 workers in Downtown Austin. Sketch a histogram.

Class LimitsClass Boundaries

Frequency

1-8 0.5-8.5 14

9-16 8.5-16.5 21

17-24 16.5-24.5 11

25-32 24.5-32.5 6

33-40 32.5-40.5 4

41-48 40.5-48.5 4 0.5 8.5 16.5 24.5 32.5 40.50

5

10

15

20

25

Commuting Distances

48.5

Distances (in miles)F

req

uen

cy

Guided Exercise 2

2. The table shows the daily temperatures for New York City, recorded for 6 days, in ℉. Sketch a line graph.

Day Temperature

1 43℉

2 53℉

3 50℉

4 57℉

5 59℉

6 67℉ 1 2 3 4 5 60

10

20

30

40

50

60

70

80

Temperature of New York City

Day

Tem

pera

ture

(℉)

Guided Exercise 2

2. The table shows the daily temperatures for New York City, recorded for 6 days, in ℉. Sketch a line graph.

Day Temperature

1 43℉

2 53℉

3 50℉

4 57℉

5 59℉

6 67℉ 1 2 3 4 5 60

10

20

30

40

50

60

70

80

Temperature of New York

Day

Tem

pera

ture

(℉)