4. A researcher investigated attitudes toward individuals in wheelchairs. The question was: Would people react differently to a person they perceived as being temporarily confined to the wheelchair than to a person they perceived as having a permanent disability? Participants were randomly assigned to two groups. Individuals in one group each worked on various tasks with a confederate in a wheelchair; members of the other group worked with the same confederate in a wheelchair, but this time the confederate wore a leg cast. After the session was over, participants filled out a questionnaire regarding their reactions to the study. One question asked, "Would you be willing to work with your test partner in the future on a class assignment?" with "yes" and "no" as the only response alternatives. What would be the appropriate significance test for this experiment?