In Example 10, the coefficient of the manure-level indicator variable m is 1.96. a. Explain why this

Question:

In Example 10, the coefficient of the manure-level indicator variable m is 1.96.
a. Explain why this coefficient is the estimated difference in mean corn yield between the high and low levels of manure, for each level of fertilizer.
b. Explain why the 95% confidence interval for the difference in mean corn yield between the high and low levels of manure is 1.96 ± 2.11(0.747).