1891. The packer packs 900 parts, checked by the OTC or manufactured by workers who have a personal stamp. The probability that the part is marked with a personal stamp is 0.1. Determine the likelihood that among them will be: a) 85; b) from 80 to 110 items with a personal stamp. Determine the most probable number of parts with a personal stamp among all the details.

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