A random sample of 173 students was asked how many songs were in their digital music library and what fraction of them was legally purchased. Overall, they reported having a total of 120,670 songs, of which 23.5% were legal. A research group found that a 95% confidence interval for the fraction of songs in students' digital music libraries that are legal is 23.3%,23.7%). The research group that conducted this survey wants to provide the music industry with definitive information, but they believe that they could use a smaller sample next time. If the group is willing to have four times as big a margin of error, how many songs must be included? A total of songs must be included. (Type a whole number.) Open original