A car dealership has stacks of response cards sitting in the waiting room of their service department. There is a sign near the stack encouraging people to take a form and send it in once the service to their car has been completed. Among the 200 responses received, 150 identified the prices at the dealership as being good or very good Which of the following is an appropriate conclusion to draw from the survey?
a. This was a convenience sample, and therefore the results cannot be trusted.
b. Because the sample was a random sample of customers, the results are statistically valid.
c. The dealership can conclude that exactly 75% of its customers think the dealership’s prices for repair service are good or very good.
d. The dealership can conclude that approximately 75% of its customers think the dealership’s prices for repair service are good or very good.
e. Because the 200 respondents chose to pick up the survey and respond, the survey suffers from voluntary response, and the results cannot be trusted.