Advice: One Way Analysis of Variance
Interval (normal) vs. Nominal (no order)
ONE WAY ANALYSIS OF VARIANCE: This is listed under the StatsDirect analysis of variance section. Assumptions are that each group is drawn from a normal distribution and that the variation within the groups is uniform. The F test is fairly robust to small deviations from these assumptions but you could use the Kruskal-Wallis test as a nonparametric alternative if there was any doubt.