Descriptive Statistics
Chapter 2: Tabular and Graphical Displays
Data visualization = describe use of
graphical displays 2 summarize &
present info about data set.
Summarizing Data for
Categorical Variables
Frequency Distribution
Tabular summary of data showing #
(frequency) of items in each of several
non-overlapping classes. Pie Chart
Use relative freqs 2 subdivide circle
in2 sectors correspond 2 relative freq
each class.
Relative frequency of class = fraction
/proportion of observations belonging
2 class.
Percent Frequency: relative frequency
multiplied by 100.
Degrees = Relative Freq x 360º
Summarizing Data for
Quantitative Variables
Frequency Distribution
Bar Charts Tabular summary of data showing #
(frequency) of items in each of several
Graphical display of categorical data
summarized in freq, relative freq, or % non-overlapping classes.
Three steps 2 define classes 4 freq
freq distrib.
distribution with quantitative data:
1. Det # of non-overlapping classes.
Usually btw 5 & 20 classes.
4 larger # of data items (n ≥ 30) =
larger # of classes req.
4 smaller # of data items (n < 30), as
few as 5/6 can summarize data.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller amywallace. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R50,00. You're not tied to anything after your purchase.