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How do you Compute Var(Y) and Cor (Y,X) with the given data?

Constant Variable Coefficient = 0.203311 s.e. = 0.0976 t-test = 2.08 p-value = 0.0526

X Variable Coefficent = 0.656040 s.e. = 0.1961 t-test = 3.25 p - value = <0.0038

n = 19 R2 = 0.397 adjusted R2 = 0.362 sigma-hat = 0.0566 df = 17

SSR = 0.358 SSE = 0.0544

Update:

based on some other stuff i have looked at i think Var(Y) can = SST

which would be simple SSR + SSE 0.0902, am I correct here?

Update 2:

do i take the sqrt of the SST so the Var(Y) would be 0.3003

Update 3:

Lobo if I had y-bar and y i would do it this way, this is why I am having problems with this. The only info I have is what I put above.

Update 4:

I have no clue what you guys are talking about. Let me see if I can write it out to help me more. The Constant Variable is B0 and the X is B1. I don't see how you are getting a y mean.

2 Answers

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  • efqy
    Lv 7
    1 decade ago
    Favorite Answer

    Yes, SST = SSR + SSE, but be careful to make sure you add correctly, however, SST is a sum of squares, not a variance. You need to do something to it.

    As for the correlation ... here's a couple of hints:

    - what's the symbol for sample correlation?

    - be careful with the sign

    ===

    SST is.not.variance.

    Look at the formula for variance (at least google it) See how it is different from SST.

    You DO NOT NEED the mean of y.

    You need a correlation. You already have a number that is closely related to correlation. Look more closely at R^2. What is it? What does it measure?

  • 1 decade ago

    SST(corrected)=sum(yi-mean of y)^2

    "if I had y-bar and y i would do it this way, "

    I know

    I was wanting to say that what you have there in table, SST(corrected) is sum(yi-mean of y)^2, which looks like the variance, except you have do do something

    you are close to the answer

    "The Constant Variable is B0 and the X is B1."

    No, the B1 is the coefficient of X(the slope) B0 is the intercept of the linr

    So you have the regression equation

    Y=B0+B1*X

    "I don't see how you are getting a y mean."

    I didn't say you are getting a y mean. I didn't say you have to calculate y mean I just explained to you what means that SST. In other words, how was calculated by the program.

    efqy said "SST is a sum of squares, not a variance."

    Looked in any place(book, internet) where the variance is defined and see it it is only a sum of squares and what is the difference

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