Assume that we measure a physical ~mntity x with a measuring device whose accuracy is ~ (i.e., whose prtniucers guarantee that the difference a: ~ between the actual value :r and the measured value d{ms m~t exceed 5). If the result of this measurement is ~, then Ix~ssible values of a: fiwm an interval [~-~,~+~]. Suppose nnw that we know that a physical qtiantity y is a function of the physical ...