A Tool Manufacturer Tests Three Types of Cutters Used in a Lathe

Multiple Choice

A tool manufacturer tests three types of cutters used in a lathe operation. One type is a laminated steel cutter made of very hard high-carbon steel sandwiched between two softer steels. Another is a special high-speed steel cutter developed using powder metallurgy. The final one is made from cryogenically treated steel. Cutters of each type are tested to see how long they will last (in hours) in continuous operation until they need to be sharpened. The times are recorded for each cutter used in the study, and the results are given below. The value of the Kruskal-Wallis statistic H for these data is:

A) 2.75.
B) 3.20.
C) 4.76.
D) 5.42.