A textile mill has a large number of looms. Each loom is supposed to provide the same output of cloth per minute. To investigate this assumption, five looms are chosen at random, and their output is measured at different times. The following data are obtained:

(a) Are the looms similar in output? Use a = 0.05.
(b) Estimate the variability between looms.
(c) Estimate the experimental error variance.
(d) Analyze the residuals from this experiment and check for model adequacy.

Loom Output (Ib/min) 4.2 1 4.0 4.1 4.0 4.1 3.9 3.8 3.9 4.0 4.0 4.2 4.1 4.0 3.9 4.1 4 3.6 3.8 4.0 3.9 3.7 3.8 3.6 3.9 3.8 4.0