True.
When testing a hypothesis involving three or more means, the appropriate test is a one-way ANOVA (Analysis of Variance). ANOVA is a statistical method that compares the means of two or more groups to determine if there is a significant difference between them. In the case of a one-way ANOVA, we are comparing the means of one variable across multiple groups or categories.
The one-way ANOVA test allows us to determine if the differences between the means of the groups are significant enough to reject the null hypothesis, which states that there is no significant difference between the means. If the p-value obtained from the ANOVA test is less than the chosen level of significance, we reject the null hypothesis and conclude that there is a significant difference between at least two of the means.