First I want to say thanks for the information and expertise that y'all are willing to share. I am going to be brave and share my confidence interval programs for the TI-82 with you. They are called CI1SAMP and CI2SAMP. They both use subroutines which I got from the TI site. GAMMA and TSUB were written by Michael Lloyd of Henderson State, and ZSUB is basically his ZVAL program. I do want to give credit where credit is due :-)!
Here are the two programs and the necessary sub-programs. I am attaching the files as UUE encoded file to this email. The files are grouped (named CONFINT.UUE) so you will need the Graph-Link to unencode and ungroup them. I have "protected" the files, but only to prevent students from losing lines out of it.
A couple of pieces of info about the programs:
1) Both of them start with a clear home screen and line that tells which program it is. I built in a pause at this point. Simply press [enter] to continue the program. 2) The students will have to choose whether to use Z or T, but the program will then calculate the appropriate critical value for either distribution - regardless of confidence level. **I know there have been recent discussions concerning the use of z and/or t, but this choice will allow the students to get the answers that the textbooks give.** 3) For "LEVEL?", they need to enter it in decimal form (.95 instead of 95%) 4) For the proportions, they will need to enter the number of successes and not the probability of success. I did it this way since that is the way the TI-83 does it.
These do not show a graphical response, but I'm sure that could be added fairly easily. I just haven't had the time. Neither have I had the time to make the necessary changes to do a hypothesis test. Surely a few modifications to these programs will be sufficient. I am going to try to do that this weekend.
Let me know what you think of these. I don't *think* there are any mistakes in them, but if you discover any problems, please let me know (my students are already using these). If there are any problems with the grouped encoded version (with all the mail systems out there, you never know), email me and I will send an ASCII version.
Jacki Jonas Math/Stats Instructor Northeast State Technical Community College Blountville, TN