Final answer:
The average response rate for first mailings of questionnaires is around 20%, although this can vary based on several factors such as non-responses and incomplete mailing lists.
Step-by-step explanation:
The typical response rate for first mailings of questionnaires is approximately 20%. Response rates for questionnaires can be quite low due to a variety of factors, such as the potential non-response from recipients and the possibility of incomplete mailing lists. For instance, a sociologist conducting a study on women's opinions about government funding for daycare mailed out 100 questionnaires and received 68 back, which is a 68% response rate, notably higher than the typical response but not necessarily common. It is important for researchers to consider these challenges when designing studies and interpreting their results.