If m angle 1 = (6x + 25), and m angle 4 = (10x - 11), find m angle 1.

Aparticular telephone number is used to receive both voice calls and fax messages. suppose that 25% of the incoming calls involve fax messages, and consider a sample of 25 incoming calls. (a) what is the expected number of calls among the 25 that involve a fax message?