# Formula for confidence interval in multi-variable regression

What is the formula for calculating the confidence interval for the expected value of $\hat{y}$ in a multi-variable regression model.

In other words, I'm looking for the following formula just for multi-variable regression: $$\hat{y_i} \pm t _{1-\frac{\alpha}{2}, n-2} \cdot \sqrt{MSE} \cdot \sqrt{\frac{1}{n}+\frac{{(x_i-\bar{x}})^2}{s_{xx}}}$$

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Standard stuff but a bit laborious to write out. I've started on it....... – Michael Hardy Feb 12 '13 at 22:04