Respuesta :
As a result of economic growth during the 1950s, the percentage of Americans who were in the middle class "increased dramatically". This was due primarily to the fact that there were far more jobs available, since World War II had helped create them.
I believe the answer is: Increased dramatically
Middle class refers to the group of people who do not necessarily rich, but had enough wealth to sustain their living comfortably. During the economic growth, many people received an increase in their salary which lead to the rise of the middle class.