Final answer:
The question regarding the plumber's earnings is not answerable with the provided information. However, using a similar example with Ethan's earnings, the independent variable is the hours worked, the dependent variable is the total earnings, the y-intercept is a flat fee of $25, and the slope is $20 per hour worked.
Step-by-step explanation:
The plumber's total earnings on Tuesday for five repair jobs and hourly pay exceeded $550. This statement involves basic algebra to determine the plumber's hourly wage if the repair jobs are fixed in their earnings contribution. To answer this question precisely, more information is needed, for example, how much he earns per repair job or the total number of hours worked on that day. As provided, the question does not give enough details to narrow down to one of the provided choices (a. $95, b. $100, c. $110, d. $120).
However, if we refer to a similar problem involving Ethan, we can discuss linear equations. In Ethan's case, the linear equation that expresses his total earnings per visit is y = 25 + 20x. Here, the independent variable is x, which represents the number of hours worked, and the dependent variable is y, which represents the total earnings per visit. The y-intercept of this equation is $25, which is the flat rate charged for a visit regardless of the hours worked. The slope of the equation is $20, indicating the charge per hour of work. Interpretation: Ethan earns a flat fee of $25 for each repair visit plus an additional $20 for every hour of work he performs.