quant: prediction interval prediction, replace, standard, understand

dvilayphet

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.