(16) To test whether the mean time to mix a batch of adhesive is the same for machines produced by four manufacturers, TiteBondMax obtained see below on the time (minutes) needed to mix the materials. Test whether the machines have equal mean mixing time at proportional to = 0.01.

Manufacturer

A 25 23 21 23

B 23 21 23 24

C 25 25 25 21

D 28 27 28 29

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