The data of Exercise 13.25, in which x = milk temperature and y = milk pH, yield...

The data of Exercise 13.25, in which x = milk temperature and y = milk pH, yield

a. Obtain a 95% confidence interval for α+ β(40), the mean milk pH when the milk temperature is 40°C.

b. Calculate a 99% confidence interval for the mean milk pH when the milk temperature is 35°C.

c. Would you recommend using the data to calculate a 95% confidence interval for the mean pH when the temperature is 90°C? Why or why not?