A potato chip manufacturer was having problems with the Weights and Measures inspectors after the inspectors found some bags containing less than the required $42\mathrm{.}5$ grams $($formerly $1\mathrm{.}5$ ounces$)$ of chips. In response, the manufacturer had increased the weight setting on the bagging machines to $50$ grams, but were now over$-$packing the bags and, consequently, giving away chips.according to the three rules of thumb, how many bags per $1,000$ are expected to be below the required minimum weight of $42\mathrm{.}5$ grams?