A remodeling contractor located in a small community had developed a relatively inexpensive type of storage shed and wanted to determine the likely level of demand for the sheds among local homeowners before he began producing and marketing them. Because the population of homeowners was not easily identifiable in the telephone directory and because it would be very inefficient to screen for homeowners due to the fact that it was a college town with the associated high proportion of renters, he didn't want to use a telephone survey. Although he could purchase a mailing list of homeowners in the relevant zip code areas, the cost of mail surveys was prohibitive. Because of these constraints, the contractor decided to collect data via an area sample and a residential drop-off survey. That is, for randomly selected neighborhoods, local college students working for the contractor would approach each household in the neighborhood, determine whether or not the resident was the homeowner, and, if so, ask him or her to complete a short written survey that the student would pick up later in the evening. If no one answered the door, the worker was to leave the survey (with instructions) at the door and to return later to pick it up.
At the conclusion of the project, 438 homes had been approached, with the following outcomes: 212 completed surveys, 31 refusals, 78 residents that rented the residence, and 117 not-at-homes. What was the response rate on this project?