We already know that 0.5 of an hour, or half of an hour, is 30 minutes. We also know that 3 dozen equals 36. With this information, we can conclude that Natalie can make 72 cookies in one hour. 72 times 5 is 360. 360 divided by 12 is 30, so, Natalie can bake 30 dozen, or 360, cookies in five hours.