14.23 With reference to Example 2, Chapter 2, use the U statistic to test the null hypothesis of equality versus the alternative that the distribution of copper content from the first heat is stochastically larger than the distribution for the second heat. Following the approach in Exercise 14.22, it can be shown that the exact distribution gives P(Ui ≥ 19 ) = 0.033. Use this as the level of significance.