Question

iv) A machine is set to produce nails of length 20 mm. A random sample of 12 nails was taken for quality control purposes. The lengths of the nails were measured and the lengths (in mm) are listed below. 20.3, 19.8, 20.1, 20.4, 20.2, 20.1, 19.9, 20.1, 20.3, 20.1, 19.9, 20.2 a) Assume a nail is equally likely to be longer or shorter than 20 mm. What distribution could be used to model the number of nails longer than 20 mm in the sample? b) Calculate a tail probability that measures how unusual it would be to observe as many nails longer than 20 mm as in the sample. c) Does this sample provide evidence that the nails produced by this machine are longer than 20 mm?

Answer 1

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