The distribution of actual weights of $8\mathrm{.}0-$ounce chocolate bars produced by a certain machine is normal with a mean of $8\mathrm{.}1$ ounces and standard deviation of $0\mathrm{.}1$ ounces. The proportion of chocolate bars weighing between $8\mathrm{.}1$ and $8\mathrm{.}3$ounces is:a$)0\mathrm{.}819$b$)0\mathrm{.}636)0\mathrm{.}477$d$)0\mathrm{.}136$e$)$Answer choice not given