The following information is available for two samples selected from independent and similarly shaped rightskewed populations:

Sample 1: n1 = 5,1.12.32.93.614.7

Sample 2: n2 = 6,2.84.44.45.26.018.5

Assuming this is a two-tail test.

1,the null hypothesis that should be used is?

2,the rank given to the last observation in the sample 2 (18.5) is?

3,at the 0.05 level of significance, determine the critical values for the Wilcoxon rank sum test statistic.