Final answer:
Today, a single farmer or rancher can feed many more people than in 1940, with one farm worker in the U.S. in the 1970s able to feed 50 people and an Australian farmer up to 85 people.
Step-by-step explanation:
In 1940, farmers and ranchers fed an average of 19 people annually. Today, due to technological advances and more efficient agriculture practices, a single farmer or rancher feeds significantly more individuals. For instance, in the 1970s in the United States, one farm worker was responsible for producing enough food to feed 50 people. In Australia, which is an extreme case, one farmer can produce enough food for 85 people, with two-thirds of these individuals living overseas. It's also worth noting that most of the cereal grain produced today is used to feed livestock rather than for direct human consumption, with less than 20 percent of the food energy from the grain reaching humans.