Suppose that 20% of students at have listened to a music album Additionally, suppose that, to gauge interest in the band, a major record label randomly samples 400 students. a. (4pts) Approximate the probability that less than 21% of the sampled students have listened to the album? (Note: Round final answers to 4 decimal places.) b. (2pts) Is it appropriate to use a normal distribution approximation to answer question a.?.