First, determine the predicted mean of the response. Then, examine the prediction interval to determine a range of likely values for a single future value.
The fitted response value (fit) is the point estimate for the specified variable settings.
The prediction interval (PI) is a range that is likely to contain a single future response for a specified combination of variable settings. If you collect another data point at the same variable settings, the new data point is likely to be within the prediction interval. Narrower prediction intervals indicate a more precise prediction.
Use the marginal prediction interval when you don't know the actual levels of the random factors. Use the conditional prediction interval when you know the specific combination of the random factor settings.