Least Square Analysis (LSA): How to do it with Cricket Graph

 

1.- Start Cricket Graph: a spread sheet will appear.

2.- Enter your x-values in Column 1 and the corresponding y-values in Column 2.

3.- From the Graph menu, select New Graph -> Scatter

4.- In the New Scatter Graph window, select Column 1 as the Horizontal (X) Axis, and Column 2 as the Vertical (Y) Axis. Then click

5.- From the Options menu, select Curve Fit...

6.- In the Curve Fit window, chose Linear from the Method pull-down menu.

7.- Make sure that Display Equation is selected (black rhomboid), and r is chosen in Coefficient Display (r is the Correlation Coefficient, the closer to 1 the better the fit of your data points to a straight line). Click

8.- A straight line will appear in your graph and an equation of the form y=mx+b will be displayed, where m is the slope of the line, and b the y-intercept.

9.- You can use these m and b values for your calculations but remember, graphs should be handmade!

 

You can find Cricket Graph installed in the computers in room 308 Havemeyer. This computers are there for you. You can also use them for word processing. This room is supposed to be open weekdays form 9am to 5pm. If the door is closed, ask someone in room 318 to open it for you.

This is what you have to do to start Cricket Graph in those computers:

1.- From the Select a setup window, choose General Chemistry Lab and click

2.- When prompted for a password enter 308.

3.- Click on the Cricket Graph III button. (If you are prompted for another password, do not enter anything. Just click )

4.- Remember to quit the program and the setup after you are done.

Enjoy!