## Hector Plotquin

### Hector Plotquin

Prof. Hector Plotquin, LACC Mathematics Department

#### Office Hours / Class Schedule Spring 2019

Time Day Course Room
9:35 - 10:45 am M-T-W-Th Math 167: Pre-Statistics Class section 22113 FH 121
11:10 am - 12:20 pm M-T-W-Th Math 261: Calculus 1 Class  section 20434 FH 121

Online Course Math 167: Pre-Statistics Class section 24780
12:30 - 1:30 pm M-T-W Office Hours FH 101-F
12:00 - 1:30 pm 2nd Tuesday Aademic Rank Committee Meeting FH 100
12:45 - 1:45 pm 2nd Thursday
• Feb. 14
• Mar. 14
• Apr. 11
• May. 9
• Jun. 13
• Aug 8
• Sep 12
• Oct 10
Mathematics Department Meeting FH 100
In this video, you will learn the basics of StatCrunch
including calculating basic summary statistics,
constructing simple graphs, interacting with those graphs,
and copying StatCrunch results into other applications.
StatCrunch is a web-based statistical software package
for analyzing data that works on any desktop browser,
such as Chrome, Firefox, Internet Explorer, or Safari.
StatCrunch also works with web browsers on smartphones
or tablets running iOS, Android, and other mobile operating
systems.
For this video, the dataset I'll be using
is called Responses to Is college worth it?
This dataset contains information
collected from a survey conducted at StatCrunch.com.
Respondents to the survey were asked
if college was worth the cost.
With the possible answers being yes, no, or unsure.
Respondents also provided their gender, age,
and if they were a current college student.

All right, now let's perform some basic operations
in StatCrunch.

The Stat menu contains a number of procedures
for Summary Statistics, Tabulation, Hypothesis Testing,
Confidence Intervals, Regression, and much more.
With this dataset, I'll consider the task of computing summary
statistics for the mean and median ages of the respondents.
I'll choose Summary Stats.
Columns.

And now I'll select the Age column.

I'll click Compute.

And StatCrunch generates a table of summary statistics.
The mean age of respondents is shown to be roughly 29.31.
And the median age of respondents
is shown much lower, at a value of 23.

To compute separate summary statistics
for each value of gender, back under the Options menu,
I'll choose Edit.
This takes us back to the original window
where we set up our table.
Now under Group by, I'll choose Gender.

And click Compute.

The mean age of female respondents
and the mean age of male respondents
are both very close to 29.3.
The median age of both genders are exactly 23.

The Graph menu contains a number of options for displaying data
in a variety of formats.
To summarize how respondents felt about college being
worth the cost, under the Graph menu,
I'm going to choose Bar Plot with Data.

I'm going to select the Good column, which
represents Is college worth it?
And click Compute.

In this case, the plot indicates the overwhelming majority
of respondents said that college was worth the cost.
To break out these responses by gender,
I'll go back under the Options menu for the graph.
Choose Edit.
And in the Group by box, choose Gender.

I'll click Compute.
Now the split bar plot, shown, splits the original responses
coded by gender.
Note the majority of those who answered yes were female.

Most graphics in StatCrunch are interactive.
This can be a very powerful feature.
So for example, to identify the females who
said college was worth it, click and drag the mouse
to form a rectangle which overlaps that bar.

The selected data values are now highlighted in the graph,
and also highlighted in any other graphs produced.
The corresponding rows are also highlighted in the data table.
Clicking the Down or Up buttons in the lower left hand corner
will scroll the data table to show the next
or previous selected rows.

This is especially useful when there
is a small number of rows that have been
selected in a large data table.
Adjacent to these two Arrow buttons, the value of 582 rows
indicates how many rows have been selected.
To turn off highlighting, I'll click the Clear button
in the lower left hand corner of the screen.
Both tabular and graphical results
can be saved to your My Results listing at StatCrunch.com,
To copy this bar plot, under the Options menu,
I can choose Copy.

To finish copying the image, follow
the tip provided for your platform as shown.
After the image is copied, it can
be pasted into any other application such as Microsoft
Word or PowerPoint.