Confidence intervals for the mean response. Figure 10.7 shows the upper and lower confidence limits on a graph with the data and the least-squares line. The 95% confidence limits appear as dashed curves. For any x*, the confidence interval for the mean response extends from the lower dashed curve to the upper dashed curve. The intervals are narrowest for values of x* near the mean of the observed x’s and widen as x* moves away from .
FIGURE 10.7 The 95% confidence limits (dashed curves) for the mean response for the physical activity study, Example 10.7.