High schoolers at a given high school show the following preferences for the one sport in which they are most interested: 30% prefer football, 25% prefer basketball, 11% prefer baseball, 5% prefer soccer, 3% prefer track, and 26% have no interest in any sport. A total of 450 students attend this high school. The athletic director's survey of the current entering class shows the following preferences: 105 football, 117 basketball, 60 baseball, 36 soccer, 25 track, and 107 who are not interested in any sport. Do the sport preferences of this year's entering class differ significantly from past students' preferences?
a. Create a table of observed and expected frequencies.
b. Calculate χ2.
c. At what level of confidence can you reject the null hypothesis?