A pool supply company sells 50-pound buckets of chlorine tablets. A customer believes that the company may be underfilling the buckets. To investigate, an inspector is hired. The inspector randomly selects 30 of these buckets of chlorine tablets and weighs the contents of each bucket. The sample mean is 49.4 pounds with a standard deviation of 1.2 pounds. The inspector would like to know if this provides convincing evidence that the true mean weight of the chlorine tablets in the 50-pound buckets is less than 50 pounds, so he plans to test the hypotheses H0: μ = 50 versus Ha: μ < 50, where μ = the true mean weight of all 50-pound buckets of chlorine tablets. The conditions for inference are met. What are the appropriate test statistic and P-value? Find the t-table here and the z-table here.

t = –2.74. The P-value is 0.0031.
z = –2.74. The P-value is 0.0031.
t = –2.74. The P-value is between 0.005 and 0.01.
z = –2.74. The P-value is between 0.005 and 0.01.