The press release titled "Keeping Score When It counts: Graduation Rates and Academic Progress Rates" (The Institute for Diversity and Ethics in Sport, March 16, 2009) gave the 2009 graduation rates for African-American basketball players and for white basketball players at every NCAA Division I university with a basketball program. Explain why it is not necessary to use a paired t test to determine if the mean graduation rate for African-American basketball players differs from the mean graduation rate for white basketball players for Division I schools.