Can anyone jog my memory on how to:

1) graph a regression line corresponding to a stat-plot? (line of best-fit)
2) solve for an expected value of x on said regression line?

I know how to edit the list, graph the stat plot, and come up with the regression equation. I just don't know how to graph the line. It's been awhile.

p.s. most TI-83 functions of this sort are the same as TI-84 and TI-84+

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1) graph a regression line corresponding to a stat-plot? (line of best-fit)
2) solve for an expected value of x on said regression line?

I know how to edit the list, graph the stat plot, and come up with the regression equation. I just don't know how to graph the line. It's been awhile.

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1) if you have the equation you can just plug it into y= and hit graph.

2) once you've plugged in the equation in y= you can hit 2nd, graph to see the table of values or 2nd, trace, value and type in the x to receive the y value.

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1) if you have the equation you can just plug it into y= and hit graph.

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My bad, should've been more specific. Is there a short-cut for this? I mean is there a way to do it w/o writing down or memorizing the equation? Something about L1,L2,Y1...etc, but I don't remember the exact steps

haha, is your equation THAT long? i can't recall a way other than that. you can hit y=, type a little bit of what you remember, quit back to the home screen, go back to y= and type a little more if you can't memorize it and don't want to write it down i suppose.

y=6.928878191(1.140762873^x) is a typical equation. So yes, it's THAT long...when you have 4 of these to do in 15 minutes and each data set has 16 points or more.

ok, i found out the other way to import it:

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You can write these values down and then go into the Y= menu, then manually type it.

OR, you can import these values, letting the calculator copy them in for you. To do this, hit the y= key. (Clear out any equations currently in here.) Put the cursor to the right of \Y1 = . Let¹s find the linear regression equation and put it here.

Hit the VARS key located just below the down arrow key. Go to #5, statistics, and enter this. See the new menu at the top? The regression equation is under the EQ menu, so select EQ using the right arrow key. Now, choice #1 is RegEQ... select this one, then hit ENTER. Your regression equation should have been copied into the Y1 = section of the calculator, and it should be in the form y = ax + b. Now, hit GRAPH, and you should see the line of regression cut through the scatterplot.

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