Final answer:
C. Analysis of variance
Analysis of Variance (ANOVA) is the statistical method used to compare the means of two or more groups in an experiment to determine if the differences are significant or due to chance.
Step-by-step explanation:
The set of statistical procedures designed to compare two or more groups of observations to determine whether differences are due to chance or experimental manipulation is called Analysis of Variance (ANOVA). Specifically, a one-way ANOVA tests the null hypothesis that several population means are equal against the alternative hypothesis that at least one mean is different. The test uses the F-distribution to analyze statistical differences between groups and is suited when comparing the means of three or more independent (unrelated) groups.
In an ideal experimental design, the control group is used as a basis for comparison, helping to account for chance factors by keeping such factors constant. On the other hand, the experimental group is exposed to the experimental manipulation, allowing researchers to observe the effects of the independent variable on the dependent variable. By comparing the two groups, we can infer if the observed differences are statistically significant or due to random variation.