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Question
A manufacturer of industrial plywood has a contract to supply a boat maker with a large amount of plywood. One of the specifications calls for the standard deviation in thickness to not exceed .03 inch. A sample of n = 30 sheets was sampled randomly from a recent production run. The mean thickness was right at the 3/4 inch target thickness and the sample standard deviation was .05 inch. Testing at the 0.05 level of significance, which of the following is true?
A) The test statistic is approximately 80.56.
B) The critical value is approximately x2 = 43.773.
C) The test statistic is approximately 48.333.
D) Based on the sample data, there is no evidence to suggest that the plywood is not meeting the specifications.
Answer
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