Finding Confidence Interval for Mean Predicted Value From the expression given in this section for the margin of error corresponding to a prediction interval for y, we can get the expression which is the standard error of the prediction when predicting for a single y, given that x 5 x0. When predicting for the mean of all values of y for which x 5 x0, the point estimate is the same, but is as follows:

Use the data from Table 9-1 and extend the last example of this section to find a point estimate and a 95% confidence interval estimate of the mean number of manatee deaths from boats, given that the number of registered boats is 850,000 (so that x 5 85).