How is the value of the RMB regulated against the dollar?

I understand that currency values change. I do not, however, understand how the price of one currency (the RMB) compared to another (USD) can be kept the same. Please explain it to me.|||the Central bank of China has the yuan (RMB) pegged to the U.S. dollar. The way they do this is by buying and selling U.S dollar bonds on the open market to influence the spot rate between US $ and Chinese Yuan. Essentially, they have so much money that they "CREATE" the supply for that money by either injecting more currency into the economy (by buying U.S gov't bonds) or taking currency out of the economy (by selling U.S. gov't bonds). This keeps the value of the yuan artificially low.





The reason they do this is so that Chinese exports continue to remain cheap to U.S. importers. If China allowed their currency to float like most other countries, the value to the yuan would rise. Consequently, Chinese goods would become more expensive to Americans. This would hurt China's economy which has been expanding at an unbelievably fast pace!