I'm trying to figure out what the best statistical test to use to find the null hypothesis in this scenario?

I'm trying to figure out what the best statistical test to use to find the null hypothesis in this scenario? Joe collected a self-report questionnaire from students from three different elementary schools in his school district on their overall Attitudes toward Physical Education. The null hypothesis is as follows: There is no statistically significant difference between fourth grade boys and girls overall Attitudes toward Physical Education.