The accompanying data resulted from an experiment to investigate whether yield from a ce...

The accompanying data resulted from an experiment to investigate whether yield from a certain chemical process depended either on the formulation of a particular input or on mixer speed.

a. Does there appear to be interaction between the factors?

b. Does yield appear to depend on either formulation or speed?

c. Calculate estimates of the main effects

e. Construct a normal probability plot from the residuals given in part (d). Do the ’s appear to be normally distributed?