A firm is concerned with variability in hourly output at several factories and shifts. Here are the results of an ANOVA using output per hour as the dependent variable (some information is missing). Source Sum of Squares df Mean Square F Ratio Factory 19012.5 1 19012.5 26.427 Supplier 258.333 2 129.167 0.180 Factory*Shift 80908.333 2 40454.167 56.230 Error 8633.333 12 719.444 Total 108812.5 17 6400.735 The number of observations in each treatment cell (row-column intersection) is