machines ( denoted by / C 1, / C 2, and / ( 3 ) were selected from the plant , and 20 bags ( each supposed to be of weight 50 1b) were filled in each of the three machines . The data ( courtesy of I . Dasgupta , in the file " Packing Machine . Ext " downloadable from IVLE ) indicate the actual weight ( in pounds ) of each of the 60 bags . a . Suppose the interest lies in the comparison of the three chosen machines in the plant . Analyze the data using one - way layout with fixed effects . Your work should include ANOVA and I' test . b . What can you conclude from ( a ) ? C . Suppose the three machines were selected randomly from the plant . Reanalyze the data using one - way random effects model . Your work should include ANOVA , I test , and estimates of variance components . d . Find a 95% confidence interval for the mean weight of the bags filled in the plant