The Jаcоbs Chemicаl Cоmpаny wants tо estimate the mean time (minutes) required to process a batch of material on mixer machines produced by three different manufacturers. To limit the cost of testing, four batches of material were mixed on machines produced by each of the three manufacturers. The times needed to mix the material follow. Manufacturer 1 Manufacturer 2 Manufacturer 3 20 28 20 26 26 19 24 31 23 22 27 22 From the regression model in question 18, what is b0 and what does it mean in the context of this problem?