Problem 12.23 A manufacturing engineer wants to study the amount of time required to assemble a piece of equipment; he is particularly interested in how the assembly time varies among workers. To study this question he selects four workers at random and records the assembly times for each of the workers. Assembly Time (min) Worker 1 Worker 2 Worker 3 Worker 4 20 16 18 21 22 23 20 17 21 20 23 18 22 18 21 17 22 19 24 18 24 19 19 23

(a) Construct the ANOVA table and test the hypothesis that there is no significant variability in assembly time between workers; use α = 0.05.

(b) Estimate the components of variance.