I have said that this class is about learning how to tell stories with data.  Many stories can be told with measures of central tendency like means, medians and modes.  But when we focus on central tendency, we summarize an entire variable with just a single number or a few numbers.  What about the rest of the numbers?  If we want to get a sense of the entire distribution of a variable, we can construct a frequency distribution.  (See pp. 83-84 for details.)  This is easy to do with a PivotTable.  Then we can create a bar chart based on the frequency distribution.  Bar charts that reflect frequency distributions are called histograms.

We have done this kind of thing before.  Now we're going to go into more detail.

For homework, I would like you to: 

1. Find some data online that meet the following specifications. 
a. Pick something on a topic that is interesting to you!
b. The data should contain at least one interval-level variable.  (In fact, you might  just find ONE variable, but that variable should be interval-level.)  
c. The dataset should have at least 30 cases. 

2. As usual, press CTRL-T to create a table with your data.

3. Summarize with PivotTable. 

4. Drag the variable into the Row Labels first.

5. Then drag the variable into the Values box.  Make sure you chosen "Count of" your variable. 

6.  Aim your mouse over the Row Labels in the table itself.  click on any one of the row labels in the table and click "Group..." to create Class Intervals. Group the categories into something that you think is reasonable.  We're aiming for something that looks rather similar to the table on page 84 of the book.  It could be categories of 5 like the table on p. 84 but you might find another grouping more sensible.  Its up to you -- as long as it makes sense.

7. Once you have created the table, add an additional column to the table containing column percentages.  To do this:

a Drag your variable into the values box a second time.  (You have already done this once to get counts.)
b. Then go to the drop-down menu and select Value Field Settings... You wanto "summarize by..." count..  as before.  Then click on the tab "Show Values as.." and choose % of column.

8. Give the table a descriptive title. 

9. Make sure you save the Excel file containing the data and the table on your USB drive to bring to class. 

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