Task $4$: A tire store orders its stock for a popular winter tire once every year. The cost of a tire for the store is $$100.$ The store sells a tire for $$120$ at the regular price. The regular demand per year is $1,000$ tires, which is normally distributed with a standard deviation of $50$ tires. Customers do not prefer to buy from an older stock; hence the store does not keep the tires for the next year. The store is able to sell the excess stock at a reduced price of $$80$ per tire.

How many tires the store should order each year? $[3$ Marks$]$