In a canteen, the manager wants to collect the opinions of customers about the quality of service on a day. why would the following method not give a representative sample?
I. Questionnaires will be sent to the first 20 customers who enter the canteen.
the first 20 customers may enjoy good quality of service cuz there are only a few people in that period. The staff have more time to serve the customers. Also, the environment is more comfortable and the customers would enjoy more. Their opinions would be different from those of customers from other periods.