What are their sources of economies of scale for the world's largest firms? What is it that permits these firms to lower their average total cost (ATC) over a large range of output?

Find the Forbes list of the world's largest firms by assets:LINK : The Global 2000 2022 (forbes.com)

From the top 10 list, select three firms from three different industries and discuss the likely sources of the"economies of scale"that underlie their large size. Review the text for what is meant by "economics of scale."