Final answer:
The upper bound for the length of the fence is 137.5 meters, which is the highest length it could be before rounding up to the next meter.
Step-by-step explanation:
The question asks for the upper bound for the length of a fence which is measured to be 137 meters, correct to the nearest meter. Upper bound in this context refers to the maximum possible length of the fence before it would be rounded down to 137 meters. If the length is rounded to the nearest meter, then the upper bound must be just below the point where it would round up to the next meter; this is half a meter below 138. Therefore, the correct answer is 137.5 meters, as this is the highest length the fence could be while still rounding down to 137 meters.
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