This activity introduces "Graphical
Analysis", a proram we will make extensive use of this Year. You will
need to see me to get a copy of the data you
need.
Graph 1:
Under the Apple Menu, open up the program "Graphical
Analysis". Note that it starts you out with 3 windows: a blank
data table, a blank text window, and a blank graph. Graphical
Analysis will let you have lots of windows open at the same time,
but will only execute commands for window at a time: the active
"dark gray" window.
Click the mouse directly on the "x" in the column headed "x".
The "X" will show up in the box above (it works like a
spreadsheet). Type in the word "percentages", hit RETURN, and type
in "%". Note that the x-axis on your graph is now labeled
"percentages (%)".
Enter the data on astrology into the % column. Use the command
DATA -> Data Options to round the values in the data window to
match your data.
Get rid of the blank graph window (click in the box in its
upper left corner). Then use the command GRAPH -> New Histogram
to get a histogram. Your data are automatically plotted and the
histogram becomes the active window. Use GRAPH -> Rename
Histogram 1 to title your histogram with your team's names.
Open the Scaling dialog box by either (a) double clicking on
the histogram or (b) using the GRAPH -> Scaling command.
The program has selected what it thinks is the best way to
display the data. The histogram is scaled "from the data" (the
high and low points on the x-axis reflect the highest and lowest
numbers you typed in) and has a bin size that groups the data.
Explore changing the bin size several items, and seeing what
happens to the histogram.
The correct bin size and scaling should make patterns in the
data clear. The reason for making any graph is to help you
understand the data. In this case the data form a bell shaped
curve. Adjust the bin size and scaling to show this curve. PRINT
the GRAPH.
Calculate the mean of your data, and write it on your
print-out. Does the mean match the peak of your histogram? Answer
on your graph.
Graph 2:
Make a histogram of "Married Teens" or "Ages of Presidents".
Choose a scale and bin size that show off the patterns in your
data. Display the data to the proper rounding. Title the histogram
with your team's names. Print a copy of the histogram.