pierre reads that 20% of new car owners need to schedule a service appointment for their vehicle within 1 year of owning it. he thinks this proportion could be lower. he asks a large group of friends and coworkers and finds that 12 out of 50 people needed to schedule a service appointment for their new car within 1 year of owning it. does the sample in this situation meet all three conditions for performing a significance test using a z-statistic? why or why not