28 inches is nearer two feet than three. I agree with your conclusion.
But I don't agree with your 90% reasoning. 90% of a mile could be described as "nearly a mile", but I don't think 90% of 36 inches could be described as "nearly 36 inches". "Nearly", to me, implies that the actual measurement is close to the stated measurement AND closer than to the next convenient division either way.
In other words, "nearly a yard", "nearly three feet", and "nearly 36 inches" are not the same measurement to me. They admit of progressively less deviation from the exact measurement.