For Those that Used the TI-36X for Statistics

steelers · #1 (**permalink**) 06-28-2007, 09:04 PM

For those that used the TI-36X on Statistics:

I'm now up to the the probability section of the IC cards (about 60% through the material). I have a good grasp of the first 3 sections. So far, I have been able to figure out all the calculations on my TI-36X, with a couple of exceptions:

1) Standard Error of the Estimate - Does anybody know how to do this one on the TI-36X? It is the 2nd to last question on the Correlation/regression (section 3) portion of the IC cards. I could go through each process listed below, however, up to this point I have been able to solve all the calculations by hitting a few buttons on the TI-36X, without going through all the steps, etc. For some reason, I can't figure this one out:

"It involves finding the difference between each observed value (actual values of Y and estimated values of Y), squaring that, and adding up all those differences squared. Then you divide by the number of values to get an average, and find the square root."

2) What is the difference between the Standard Deviation for a sample or a poulation? It is a matter of hitting the oxn or the oxn-1 button on the TI-36X. Each button gives a different answer. What is the difference?

barcotta · #2 (**permalink**) 06-29-2007, 05:29 AM

Quote:

Originally Posted by steelers

For those that used the TI-36X on Statistics:

I'm now up to the the probability section of the IC cards (about 60% through the material). I have a good grasp of the first 3 sections. So far, I have been able to figure out all the calculations on my TI-36X, with a couple of exceptions:

1) Standard Error of the Estimate - Does anybody know how to do this one on the TI-36X? It is the 2nd to last question on the Correlation/regression (section 3) portion of the IC cards. I could go through each process listed below, however, up to this point I have been able to solve all the calculations by hitting a few buttons on the TI-36X, without going through all the steps, etc. For some reason, I can't figure this one out:

"It involves finding the difference between each observed value (actual values of Y and estimated values of Y), squaring that, and adding up all those differences squared. Then you divide by the number of values to get an average, and find the square root."

2) What is the difference between the Standard Deviation for a sample or a poulation? It is a matter of hitting the oxn or the oxn-1 button on the TI-36X. Each button gives a different answer. What is the difference?

I'm just about where you are and, although I'm using a different calculator, I had your exact experience. Here's my "becoming educated" take:

1. I don't think it's automated. Fortunately, it's an easy formula to remember so I think I have that one.

2. A population calculation requires that you have ALL the data. In other words, there are a total of four items to be considered and you have all four. A sample is...well...a sample. So, if they want to know how many women between the ages of 20-25 are married, they would sample something less than every woman--and you would use the sample SD calculation (with the n-1 denominator) for however many are in the sample. That was confusing as presented in IC as there was no clear transition.

steelers · #3 (**permalink**) 06-29-2007, 02:25 PM

Cool. Thanks for that. On to probabilities. Have you started that section yet?

barcotta · #4 (**permalink**) 06-29-2007, 04:27 PM

Yep--started. I know basic probability as illustrated in the first set of problems and I also went through learning how to use the permutations and combinations functions on my calculator. TI has several downloadable docs that are used for explaining and teaching and that helped a lot. I'm going to get to the end of IC with a good, but not complete, basic understanding of everything there and then I'm going to start taking the sample exams and really direct my focus wherever that leads.

steelers · #5 (**permalink**) 06-29-2007, 05:52 PM

Really? Are those docs on the TI site? Any other TI docs thatr I should know about? I know nothing about probabiltiy. Can all of these probability problems be solved using the combinations and permutations calculator functions? Up to this point, I can solve everything on the calculator, with the exception of the Standard Error of the Estimate. At least that one can easily be solved by just following some steps on the calculator, even if their is not a specific button. I really hope the last two sections do not contain a lot of calculations that can't be easily solved with the calculator. Please advise.

Johanna · #6 (**permalink**) 06-30-2007, 12:12 AM

With a bunch of us studying for statistics (and not enjoying it), maybe we should form a study group??

steelers · #7 (**permalink**) 06-30-2007, 02:50 AM

Johanna - Where are you at in the material? I'm about 1/4 of the way through the probability. The funny thing is that once I'm through the IC material I'm probably going to forget how to calculate all the stuff I figured out in the beginning. It is probably going to be a long review process.

steelers · #8 (**permalink**) 06-30-2007, 02:52 AM

Barcotta - How far into the probability section are you? Have you got to a point where you can use your calculator combinations and permutations functions to figure them out?

barcotta · #9 (**permalink**) 07-02-2007, 04:14 PM

Quote:

Originally Posted by steelers

Barcotta - How far into the probability section are you? Have you got to a point where you can use your calculator combinations and permutations functions to figure them out?

Sorry I haven't been on-line. I've been taking advantage of that flexibility this method of achieving a college degree offers! I'm still just into the beginning of probability and really haven't touched it since. I was targeting the end of June for this exam but too many things came up so it will likely (realistically) be the end of July now. I'm going on vacation next week and I'm bringing my American Gov't Cliff Notes with me (Statistics is WAY too unvacation-like!) so I'll likely try both at the end of July. Sorry I can't be of more help now--but I'll be back on-line once I've made some more headway.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode