I'm going to take a stab in the dark here, and say that for simple programs like this assignment, you would be better off using gcc from the command line.
I'm a bit of an old school C programer from a Unix background, but this should work...
Create your speed.c program using a text editor, like TextEdit, and then compile it (from a Terminal Window) like this:
gcc -o speed speed.c
This command runs the "gcc" compiler, and outputs a program (-o speed) from your source program (speed.c). Make sure your Terminal window is in the same directory as your source file (use the "cd" command to change to the directory you want).
If you get any errors, go back and edit speed.c and then fix them.
Recompile again until you don't get any errors.
When you are done, run your program, by typing this command:
speed
If you use standard printf statements for output, you should see it on the screen.
If you need to capture the output in a file, then run your program like this:
speed > csis.dat
This will put the output of your program into the file called csis.dat (that is what I assumeyou want from the assignment description). You can open this with Textedit, and see the output. I would run it the first way without the redirect first, and make sure it works with the output to your screen. Then for the final run, redirect into the file.
If you might start with a simple "hello world" program like this:
#include <stdio.h>
main ()
{
printf("Hello World!\n");
}
I don't have gcc loaded, but I think that would work. Compile it and you should get "Hello World" when you run it. Once you have this working, make some other minor changes, and you can convert this into your speed.c program assignment...