A nine-laboratory cooperative study was performed to evaluate quality control for susceptibility tests with 30-μg netilmicin disks [6]. Each laboratory tested three standard control strains on a different lot of Mueller-Hinton agar, with 150 tests performed per laboratory. For protocol control, each laboratory also performed 15 additional tests on each of the control strains using the same lot of Mueller-Hinton agar across laboratories. The mean zone diameters for each of the nine laboratories are given in Table 6.11.
Answer Problem 6.18 assuming each laboratory uses a common medium to perform the susceptibility tests.
Provide a point and
Table 6.11 Mean zone diameters with 30-μg netilmicin disks tested in nine separate laboratories
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Fundamentals of Biostatistics
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