A line has a slope of undefined which of the following points could this line pass through a. (-9,7) (9,-7)
b. (1,4) (2,5)
c. (3,-6) (7,-6)
d. (12,9) (12,6)

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?