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 mm/day were taken for 40 days.

The results are shown in the following table.

a. Compute the least-squares line for predicting evaporation (y) from temperature (x).

b. Compute 95% confidence intervals for ????0 and ????1.

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

d. Find a 95% confidence interval for the mean evaporation rate for all days with a temperature of 20◦C.

e. Find a 95% prediction interval for the evaporation rate on a given day with a temperature of 20◦C.