11. A modi cation has been made to the process for producing a certain type of time-zero lm ( lm that begins to develop as soon as a picture is taken).

Because the modi cation involves extra cost, it will be incorporated only if sample data strongly indicates that the modi cation has decreased true average developing time by more than 1 second. Assuming that the developing-time distributions differ only with respect to location if at all, use the Wilcoxon rank-sum test at level .05 on the accompanying data to test the appropriate hypotheses.

Original Process 8.6 5.1 4.5 5.4 6.3 6.6 5.7 8.5 Modified Process 5.5 4.0 3.8 6.0 5.8 4.9 7.0 5.7