NON-PARAMETRIC STATISTICS: solve

4. Two independent samples: The Mann-Whitney test (Weighting 10 points) In a quality control department they want to compare the time it takes to diagnose equipment failures using two alternative systems. A sample of 30 equipment failures is randomly assigned to be diagnosed by the two systems. The first system is used to diagnose 14 faults, and the second system is assigned 16 faults. Table 21.8 reports the total time, in minutes, required to diagnose each of the faults. No assumption can be made regarding the distribution of the total time required for these diagnoses. Using the 10% level of significance, test the null hypothesis that the two samples were drawn from populations that have the same median. Table 21.8 Time required to diagnose equipment failures (in minutes)