My variable represents the outcome of a mock-election, between three different parties(so categorical). My hypothesis is that with the information presented to the subjects, a majority will vote for party A. A simple frequency table shows that indeed most subjects (75 percent) voted for party A. Does this confirm my hypothesis/reject the 0-Hypothesis, or is there a test that I should do to show if this majority is significant? I have the feeling that there is such a test, but can not seem to figure out which one it is and how to do it in spss. Can anyone here give me advice on that? Thank you!

My variable represents the outcome of a mock-election, between three different parties(so categorical). My hypothesis is that with the information presented to the subjects, a majority will vote for party A. A simple frequency table shows that indeed most subjects (75 percent) voted for party A. Does this confirm my hypothesis/reject the 0-Hypothesis, or is there a test that I should do to show if this majority is significant? I have the feeling that there is such a test, but can not seem to figure out which one it is and how to do it in spss. Can anyone here give me advice on that?