A medical journal used a questionnaire survey to determine whether a particular change in its format would increase its readership. Sixty-two percent of those who returned the questionnaire supported that change. On the basis of this outcome, the decision was made to introduce the new format. Which one of the following, if it were determined to be true, would provide the best evidence that the journal's decision will have the desired effect? ['Of the readers who received questionnaires, 90 percent returned them.', 'The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like the format change.', 'Ninety percent of the readers who were dissatisfied with the old format and only 50 percent of the readers who liked the old format returned their questionnaires.', 'It was determined that the new format would be less costly than the old format.']