Coil winding machines. A plant contains a large number of coil winding machines. A production analyst studied a certain characteristic of the wound coils produced by these machines by selecting four machines at random and then choosing 10 coils at random from the day's output of ench selected machines. The results follow. j
i 1 2 3 4 5 6 7 8 9 10
1 205 204 207 202 208 206 209 205 207 206
2 201 204 198 203 209 207 199 206 205 204
3 198 204 196 201 199 203 202 198 202 197
4 210 209 214 215 211 208 210 209 211 210
Assume that ANOVA model Y; = Hitej (i. e., random cell means model) is appropriate.
(a) Test whether or not the mean coil characteristic is the same for all ma- chines in the plant; use = 0.1. State the alternatives, decision rule, and conclusion. What is the P-value of the test?
(b) Estimate om/(+ o) with a 90% confidence interval. Interpret your interval estimate.
(c) Test whether or not and o- are equal: use a 0.1. State the alterna- tives, decision rule, and conclusion.
(d) Estimate o? with a 90% confidence interval. Interpret your interval esti mate.
(e) Obtain a point estimate of o^2