[R] Forcing best-fit lines to go through the origin

[Jim Milks]

Dear All,

I have a rather unusual problem.  I have a set of data for a class in 
subsurface processes.  From that dataset, I must calculate the slope of 
the best-fit line (which is the parameter of interest).  The problem I 
have is twofold: 1) for the purposes of the exercise, I must force my 
best-fit line to go through the origin (0,0), and 2) the line must be 
linear, even though the data is not.  I would like to use R to help me 
calculate the line, but am unaware of any code or packages that will 
allow me to force the line through the origin.

The dataset is as follows:

    C   		C*
4.1 		17.4
6.2 		24.9
27.9 		39.5
91.1 		57.4
168.0 	75.5

Thank you in advance for any advice you can give me.

Sincerely,

Jim Milks
Graduate Student
Environmental Sciences Ph.D. Program
Wright State University
3640 Colonel Glenn Hwy
Dayton, OH 45435