Launch Logger Pro.
[If necessary, select Menu bar/File/New.]

Default configuration: Data set (X,Y); untitled graph (0-100 X, 0-100 Y).

Double-click on Data Set. Re-Name data set: "Reasons for the Seasons". Add
comments (optional): "Data sets for Washington, DC on the 21st of each
month (approximate dates of equinoxes & solstices). "Average High
Temperature" recorded at Reagan National Airport (DCA). "Angle of
Insolation" equals altitude of Sun at transit (Local Solar Noon), the
angle formed between the horizon (0 degrees) and a line of sight to the
Sun (0-90 degrees, expressed to the nearest tenth of a degree). "Duration
of Insolation" calculated by subtracting time of sunrise from sunset,
expressed in 24-hour format; time units are expressed in hours (to the
nearest hundredth-hour). Data sets current as of May 2005."

Double-click on X (in data table). Re-Name: "Day of Year"; Short Name:  
"Day"; Units: "Days". Check "Generate Column": Generate "Numeric Values";
Start: 1; End: 365; Increment: 1. [Black]

Double-click on Y (in data table). Re-Name: "Average High Temperature";  
Short Name: "Avg High Temp"; Units: [Insert Symbol: degrees]F. [Red]

Data/New Manual Column...
Name: "Angle of Insolation"; Short Name: "Sun's Altitude"; Units: [Insert
Symbol: degrees]
[Green]

Data/New Manual Column...
Name: "Duration of Insolation"; Short Name: "Daylight Hours"; Units: "hr"
[Blue]

Click on Y-axis label (on graph); select "All of the Above".

Double-click on graph. Graph Options [tab]; enter Title: "Reasons for the
Seasons".

Manually enter data (refer to activity sheet). Click "Autoscale" (see
toolbar below menu bar).

Menu bar/Analyze/Examine. Click-drag window to better location on graph 
(not covering graph lines).

Use graph to answer activity questions.