Final answer:
The assembly line was the main factor that contributed to the increased number of affordable cars manufactured in the 1920s.
Step-by-step explanation:
The assembly line was the main factor that contributed to the increased number of affordable cars manufactured in the 1920s. This innovative production method, introduced by Henry Ford, allowed for mass production of automobiles, which significantly reduced their cost. By streamlining the manufacturing process and increasing efficiency, the assembly line made it possible for more cars to be produced at a faster rate, thus making them more affordable for the general public.
Learn more about increased number of affordable cars in the 1920s