A business owner is projecting future sales growth using the arithmetic sequence formula $a_n = a_1 + (n - 1)d$. Match each variable from the formula with its correct definition in this business context.

A logistics coordinator is tracking the number of shipping containers at a port, which decreases by a fixed amount each day. If the coordinator knows the container count on Day 10 and the daily rate of decrease (common difference), what is the necessary first step to establish a general formula for the container count on any given day?

A logistics supervisor is analyzing a shipping sequence where the number of daily outgoing pallets decreases at a constant rate. To calculate the projected volume for a future day and establish a general tracking formula, the supervisor follows the two-stage application of the arithmetic sequence formula. Arrange the steps of this process in the correct order as demonstrated in the course example.

Payroll Analysis using Arithmetic Sequences

A facility manager is modeling the efficiency of an industrial air filter that decreases by a constant amount ($d$) each month. If the manager knows the filter's efficiency rating for Month 8, they must first use the general term formula to solve for the _______ (represented as $a_1$ in the formula) before they can establish the general formula for the filter's efficiency over any number of months $n$.