Use the data in Exercise 26 in Section 13.1 for the following.

a. Compute a point estimate for the mean evaporation rate when the temperature is 20°C.

b. Construct a 99% confidence interval for the mean evaporation rate for all days with a temperature of 20°C.

c. Predict the evaporation rate when the temperature is 20°C.

d. Construct a 99% prediction interval for the evaporation rate on a given day with a temperature of 20°C.

Exercise 26

In a study to determine the relationship between ambient outdoor temperature and the rate of evaporation of water from soil, measurements of average daytime temperature in °C and evaporation in millimeters per day were taken for 10 days. The results are shown in the following table.

Temperature Evaporation 11.8 2.4 21.5 4.4 16.5 5.0 23.6 4.1 19.1 6.0 21.6 5.9 31.0 4.8 18.9 3.0 24.2 7.1 19.1 1.6