Final answer:
The percent of error of the Subway sandwich is 6.25%.
Step-by-step explanation:
The percent of error can be calculated using the formula:
Percent Error = (|Measured Value - Actual Value| / Actual Value) x 100%
In this case, the measured value is 11.25 inches and the actual value is 12 inches. Plugging these values into the formula, we get:
Percent Error = (|11.25 - 12| / 12) x 100% = (0.75 / 12) x 100% = 0.0625 x 100% = 6.25%
Therefore, the percent of error of the Subway sandwich is 6.25%.