For Exercises 16.1 and 16.2, see page 16-5; for 16.3 and 16.4, see page 16-6; for 16.5 and 16.6, see page 16-8; for 16.7, see page 16-11; for 16.8, see page 16-12.
16.5 The P-value for top spas.
Refer to Exercises 16.1 and 16.3 (pages 16-5 and 16-6). Find μW, σW, and the standardized rank sum statistic. Then give an approximate P-value using the Normal approximation. What do you conclude?
16.5
μW=27.5, σW=4.7871. We found W=18, so using continuity correction, we get z=−1.88, P-value=0.0301. There is evidence to show a systematic difference in the number of rooms among the 25 top-ranked spas and the spas ranked 26 to 50 at the 5% significance level.
spas