Final answer:
The formula to calculate the projected increase of employee benefit costs by 3% in cell C13 is '=B13 * 1.03'. This formula captures the entire current amount plus the 3% increase by multiplying by 1.03, whereas the other options do not calculate the correct total projected costs.
Step-by-step explanation:
The student has asked how to construct a formula in cell C13 to calculate the annual projected employee benefit costs after a projected increase of 3% for the year 2021. The correct formula to use for this calculation in a spreadsheet application such as Excel would be option a) =B13 * 1.03.
This formula takes the current year's benefit costs from cell B13 and increases it by 3%. The multiplication by 1.03 is equivalent to calculating 100% of the original amount (the full value in B13) plus an additional 3% (the increase).
Options b), c), and d) do not provide the correct method for increasing the value by 3%. Option b) would only calculate 3% of the previous cell's value, option c) confusingly includes a cell reference that does not match the consistent pattern for the operation, and option d) references the wrong cell for the basis of the calculation.