Which way of dispensing champagne, the traditional vertical method or a tilted beer-like pour, preserves more of

Question:

Which way of dispensing champagne, the traditional vertical method or a tilted beer-like pour, preserves more of the tiny gas bubbles that improve flavor and aroma? The following data was reported in the article "On the Losses of Dissolved CO2 during Champagne Serving" (J. Agr. Food Chem., 2010: 8768-8775).

Assume that the sampled distributions are normal.
a. Carry out a test at significance level .01 to decide whether true average CO2 loss at 18 °C for the traditional pour differs from that for the slanted pour.
b. Repeat the test of hypotheses suggested in (a) for the 12° temperature. Is the conclusion different from that for the 18° temperature? The 12° result was reported in the popular media.