Final Answer:
The analysis of variance (ANOVA) is useful if you want to compare the mean incomes of people in several different jobs. Thus option A is correct.
Step-by-step explanation:
ANOVA is a statistical method used to compare means among three or more groups. In this case, comparing mean incomes of individuals in various jobs involves multiple groups (jobs) and aims to determine if there's a significant difference among these means. The formula for ANOVA calculates the variance between the group means and within the groups. By comparing these variances, ANOVA assesses whether the differences in mean incomes among various jobs are significant or if they might occur by random chance.
To illustrate, suppose we have three job categories: A, B, and C. We collect income data from individuals in each group. ANOVA calculates the F-statistic, which determines if the variation in incomes between these job categories is greater than the variation within each job category. A high F-value suggests a significant difference in mean incomes among the jobs, while a low value indicates the opposite.
By employing ANOVA, we can analyze if there's substantial evidence to support the notion that the mean incomes among different job categories are significantly different. This statistical method is specifically tailored for comparing multiple means simultaneously, making it the appropriate choice for assessing income disparities among various job groups.