In: Statistics and Probability
Derive the formula for a (1-α) level confidence interval for the Mean response E(Y|X=x*) using the simple linear regression model, where x* is a specified value for X.
Let the simple linear regression model be:
Let be the value of regressor variable for which we wish to estimate the mean response, E(Y|X=). An unbiased point estimator of E(Y|) is given as:
Thus,
We use here,
Thus, the 100(1-) percent confidence interval at X= is obtained as: