9e. Scatter Charts

CSCI N207 Data Analysis Using Spreadsheet

Department of Computer and Information Science, IUPUI

Lingma Achesonlinglu@iupui.edu

Scatter Chart• Multivariate analysis (involve two variables)• Plots x,y coordinate pairs as points so there are actually two

values associated with a single point on the chart.• Used to illustrate a dependence of one set of values on the

other. • Be able to see if there is a correlation between two variables.

– Positive correlation: one set of values goes up as the other set goes up– Negative correlation: one set of value goes up as the other set goes down– No correlation: no pattern shown

Practice

0 50000 100000 150000 200000 250000 300000 350000 400000 450000 5000000

10000

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Indiana Average Yearly Salary VS. Number of Employement

Total Employement

Avera

ge S

ala

ry• Use the Indiana salary information to find if there is a

correlation between average yearly salary and the total number of employment.

• indianaScatterChart.xlsx

Charts Summary• Given a set of data, what type of graph would

you use?• Generally speaking –

– Column/bar chart: good for comparing series of data on a single variable

– Line chart: good for looking at a trend over a period of time

– Pie chart: good for comparing the percentage– Scatter chart: good for finding the correlation

among two different variables• On same set of data, one can summarize in

different ways, and use different types of chart to convey miscellaneous information

• E.g. multipleCharts.xlsx