The survey shows that news magazines have an average of 4 to 5 readers per magazine. It can be inferred that there are about 80,000 to 100,000 readers behind the 20,000 subscribers of Music Journey. which is the premise of the above estimates? ['Most readers of Music Journey are subscribers to news journals.', 'The proportion of readers and subscribers of Music Journey is the same as that of news journals.', 'Readers usually like to read more than one type of publication.', 'News readers have similar readership to Music Journey.']