Which type of sampling method is being employed in the following example A post office manager was in charge of 11 postal delivery people He wanted to do a study on the customer s level of satisfaction for the customers he works with So he asked 3 of his delivery people to ask every person on their delivery route to rate their satisfaction of mail service on a scale of 1 to 10 Simple Random Sampling Stratified Sampling Cluster Sampling Sampling of Convenience F