The males of stalkeyed flies Cyrtodiopsis dalmanni have long

The males of stalk-eyed flies (Cyrtodiopsis dalmanni) have long eye stalks. The females sometimes use the length of these eye stalks to choose mates. Is the males eye-stalk length affected by the quality of its diet? An experiment was carried out in which two groups of male stalkies were reared on different foods (David et al. 2000). One group was fed corn (considered a high quality food), while the other was fed cotton wool (a food of substantially lower quality). Each male was raised singly and so represents an independent sampling unit. The eye spans (the distance between the eyes) were recorded in millimeters. The raw data, which are plotted as histograms below, are as follows: Corn diet: 2.15, 2.14, 2.13, 2.13, 2.12, 2.11, 2.1, 2.08, 2.08, 2.08, 2.04, 2.05, 2.03, 2.02, 2.01, 2, 1.99, 1.96, 1.95, 1.93, 1.89 Cotton diet: 2.12, 2.07, 2.01, 1.93, 1.77, 1.68, 1.64, 1.61, 1.59, 1.58, 1.56, 1.55, 1.54, 1.49, 1.45, 1.43, 1.39, 1.34, 1.33, 1.29, 1.26, 1.24, 1.11, 1.05 Corn diet (group 1): Mean (mm)= 2.05, variance (mm^2)= 0.00558, sample size=21 Cotton diet (group 2): Mean (mm)= 1.54, variance (mm^2)= 0.0812, sample size=24

A) what is the best test to use to compare the means of the two groups? why? Would using the Welchs approximate t test be better than using a two sample t test in this case ( since the variance isn\'t equal )

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