Answer :
Measurement refers to the process of determining the size, length, or quantity of something. Accuracy is how close a measurement is to the true or desired value. The lower bound is the smallest possible value in a range, while the upper bound is the largest possible value. In your context, if you have a measurement with an accuracy range specified by a lower bound of 1 and an upper bound of 4, it means the actual value could be anywhere between 1 and 4, inclusive.