The time required to complete a project is normally distributed with a mean of $80$ weeks and a standard deviation of $10$ weeks. The construction company must pay a penalty if the project is not finished by the due date in the contract. If a construction company bidding on this contract puts in a due date of $80$ weeks, what is the probability that they will have to pay a penalty? a$.1\mathrm{.}000$ b$.1/8.0\mathrm{.}500$ d$.$ o