Cameron pays $0.95 per song with his current music service. Cameron’s friend tells him of another service that has a $15 joining fee but charges $0.80 per song. At what number of songs does this new service become a less expensive option than Cameron’s current service?

At the beginning of a call to the cable company, a message tells customers, "after you finish talking to our customer service representative, you will be asked to take a five-question survey about the level of service you recieved. it would be appreciated if you could stay on the line to answer the survey questions." what type of sampling is the cable company using?