In 2016, the US Department of Agriculture established a “maximum acceptable” salmonella prevalence of 15.4 percent for chicken parts sampled at the end of a slaughterhouse’s kill line. 54 of the 154...

In 2016, the US Department of Agriculture established a “maximum acceptable” salmonella prevalence of 15.4 percent for chicken parts sampled at the end of a slaughterhouse’s kill line. 54 of the 154 largest chicken-slaughter facilities in the US failed to meet this standard in 2018. Assume that these results are representative for all large chicken-slaughter facilities. Suppose that in a random sample of 60 chicken parts from the large ACME chicken-slaughter facility (which produces 1,000,000 chicken parts per year), 45 chicken parts test negative for salmonella.

b) Estimate the number of facilities that are needed in a study to obtain 80% power to test the null hypothesis that the prevalence of failing to meet the chicken part salmonella standard among large chicken-slaughter facilities is 20%.