16.39 A study by a chemical company compared the drainage properties of two different polymers. Ten different sludges were used, and both polymers were allowed to drain in each sludge. The free drainage was measured in mL/min.

Sludge Type Polymer A Polymer B 123456789 10 12.7 14.6 18.6 17.5 11.8 16.9 19.9 17.6 15.6 16.0 12.0 15.0 19.2 17.3 12.2 16.6 20.1 17.6 16.0 16.1

(a) Use the sign test at the 0.05 level to test the null hypothesis that polymer A has the same median drainage as polymer B.

(b) Use the signed-rank test to test the hypotheses of part (a).