A MIND REVIEW

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A MIND REVIEW
By Derek Baker Michael Melson
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In this review we will look back on the
following
Quantitative vs. Categorical Data
Types of Graphs and When to Use Them
S O C S
Skewed Data and How the Mean compares to the
Median
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Quantitative vs. Categorical Data
Key Points
Quantitative data is that which can be measured
or counted as in a age, population, etc.
Categorical data is that which is not counted
such as names, addresses, etc.
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Types of Graphs and When to Use Them
Key Points
Graphs are a visual representation of both
categorical and quantitative data.
categorical Charts
Quantitative Graphs
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S O C S
Key Points
Shape Graph, histogram, boxplot, look
for.. Skewed, synthetic, modes Outliers
Affects Mean and Sx Center - Mean Vs. Median,
know when to use when Spread Sx vs IQR
- Unimodal. Bimodal
- Is it an outlier or not?

• Use mean when the graph is not skewed and there
  are NO outliers
• Use median when there are

-Range, Sx, Mean
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Skewed Data and How The Mean Compares to The
Median
Key Points
Use the mean when the graph is not skewed and has
NO outliers perfect graph. Use the median when
there are outliers and the graph is skewed.
Skewed Left
Skewed Right
10 9 8 7 6 5 4
10 9 8 7 6 5 4
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
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Jeopordy
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Quantitative Data

• Most quantitative data is displayed in a table or
  chart such as the one below

Quarterly Profit Margins (in millions)
Month
Week
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Categorical Data

• Most Categorical data is displayed in a list or
  database. Categorical data can include a
  phonebook, an address book and a list of
  consumers.

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a.Frequency table b.Bar Chart (Segmented not
shown) c.Pie Chart d.Contingency Table
Categorical Charts
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a. Histogram (Relative Frequency Histogram) b.
Stem-and-leaf Display c. Dotplot d. Timeplot
Quatntitative Graphs
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