Organic milk is stocked at a grocery store each week. At the end of each week, unsold organic milk price is reduced by $30\%$ ?and the store can sell the unsold organic milk fully at this lower price. If weekly demand for organic milk is normally distributed with a mean of $200$ ?gallons and standard deviation of $20$ ?gallons, find the price for which a fresh gallon of organic milk sells. Assume that the store has a service level of $97\mathrm{.}5\%$ ?and purchases organic milk for $ $4\mathrm{.}95$ ?per gallon.