quant: prediction interval

prediction, replace, standard, understand

If we're given an ANOVA table, and it asks for a prediction interval, should we use:

mean +/- (given standard error)(t stat)

or should we replace the given standard error with sqrt((standard error^2)((1 + (1/n) + ((x - mean)^2)/((n-1)(variance))))

I don't understand when to use one or the other.

flyinggirl

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2^#

发表于 2011-7-11 19:30 | 只看该作者

When n is too large you can use the given error value. If not, then unfortunately you'll have to calculate the satndard error of the estimate using the formula you mentioned above.

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BelalM

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3^#

发表于 2011-7-11 19:30 | 只看该作者

difference is prediction interval for a variable in the regression (which is the first equation)

and 2nd equation is prediction interval for a forecast made using the regression.

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quant: prediction interval

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