Here's the question you clicked on:
StClowers
Height (ft) Interval after (min) 96 68 111 80 76 66 91 72 66 58 108 79 116 84 91 79 The data show the time intervals after an eruption (to the next eruption) of a certain geyser. Find the regression equation, letting the first variable be the independent (x) variable. Find the best predicted tie of the interval after an eruption given that the current eruption has a height of 84 feet. Use a significant level of 0.05. A. What is the regression equation? Ŷ = __ + ___x B. What is the best predicted value? Ŷ ͌ __ minutes
Have you found a regression equation before? Do you happen to have a TI-84 calculator available to you?
Have you used it before to calculate a regresstion line in the form y=ax+b?
i am a rookie at it so i have not
Have you previously used the STAT key, which brings up a menu, one of the items on which says EDIT?
If you'd press STAT and then EDIT, your calc will display a couple of columns. would you try that, please? are there numbers in the columns, or are they empty?
there are numbers under L2
If you know how to clear out the numbers in column L2, please do it. Otherwise we may be able to find the regression line without clearing L2.
Here's your data: 96 68 111 80 76 66 91 72 66 58 108 79 116 84 91 79 copy everything from the 1st col. into L1; copy everything from the 2nd col. into L2. Any questions about this, please ask.
Now press STAT again. You should see a menu; the middle item at the very top should say MATH or CALC. Does it?
Please move the cursor to cover MATH OR CALC.
tHEN press the character " 4 ". Your calculator will exevcute option #4, whivch is "linear regressin Line" or something like that.
Does it display a value for a and a value for b?
cool. You're right up there with the best.
well i hit enter and it went to LinReg(ax+b) and thats it
have you pressed ENTER yet?
Has the calc. responded with ifnormation / information?
oh yes it has...i had to hit enter again...it says: y=as+b a= .4601084431 b= 29.82726569
What we're hoping for is a screen that gives you... cool. Now write this equation: y=0.461x + 29.827. That is your regression equation.
yay! That was it, now its asking me the next question
This problem asks for the regression equation in slightly different format. It asks that you present b first, and then a. So, to asnwer this quaetion, type in 29.827 for the first blank and 0.461 in the 2nd blank. How
Now write down on paper that same regression equation.
type here what the 2nd question asks you for.
ok. What is the best predicted value? Ŷ ͌ __ minutes
Thisis very important: You're going to use the regression equation to PREDICT what the value of y (actually, of "y hat") is when x = 84, was it? Go back to the original question and ascertain the x value.
On paper, write the regression equation, subbing 84 for x. Calculate y hat.
You're done! My regret is that we don't have time to review this whole problem so that every quantity and concept is clear to you. Hope you'll review our conversation and take notes on it so that you'll be able to do problems like this on your own.
wow! Thank you so much. I have the others posted but we can do those tomorrow. I REALLY appreciate your help!!
As much as I'd like to continue, it's past my bedtime! Don't know when I'll be available tomorrow, but I do expect to be on then and now. I'm so glad you've gotten this one problem behind you and are feeling better. You're most welcome!
but one more thing: It ask me to round one decimal place so that would be 69, correct?
No, that'd be 68.6. That's to 1 decimal place accuracy.
oh gotcha, ok thanks you again! Gnight!! This really helps. I feel better
Again, I'm so glad! Good night. Bye for now! Over and out.