Question

A shipment of 1000 cartons of fruit arrives at a distribution center with a nominal weight of 10 lbs per carton. A sample of 20 cartons is selected and weighed. The average weight of the sample is 9.8 lbs. From past shipments, it is known that the standard deviation of weight among cartons is 2 lbs. The auditor wishes to test the hypothesis that the average weight of the cartons matches the nominal value vs. that the cartons are underweight at α = 0.05. The test statistic (z-score) is:

	a) –0.10
	b) –0.45
	c) –1.0
	d) –1.65

Answer 1

Solution:

Test statistic is z = -0.45 (option b is correct)