A developmental biologist removed the oocytes (developing egg cells) from the ovaries of 24 frogs (Xenopus laevis). For each frog the oocyte pH was determined. In addition, each frog was classified according to its response to a certain stimulus with the hormone progesterone. The pH values were as follows:

Investigate the relationship of oocyte pH to progesterone response using a Wilcoxon-Mann-Whitney test at α = 0.05. Use a non directional alternative.

Positive response: 7.06, 7.18, 7.30, 7.30. 7.31, 7.32, 7.33, 7.34, 7.36, 7.36, 7.40, 7.41, 7.43, 7.48, 7.49, 7.53, 7.55, 7.57 No response: 7.55, 7.70, 7.73, 7.75, 7.75, 7.77