Solution of problem N406 Laplace probability theory

Solution of problem N406 Laplace probability theory

406. In the sequence of signs forming the message transmitted through the communication channel, any sign due to interference is independently distorted with a probability of 0.2. 10,000 characters have been independently transmitted. What is the probability that in the accepted sequence there will be from 2000 to 2100 distortions?

Additional information:

Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)