An ACT test-prep center claims that their program increases students' scores by more than 2.5. points after taking their class. You collect data on four students before and after the program and find the following results: Garret Ken Kama Roman Test Score Before 15 30 22 15 After 30 34 28 17 The calculated Standard Deviation of the Differences or Sp = 5.74. Test the validity of the test-prep center's claim at the 5% significance level under the assumption that the ACT test scores are normally distributed. Round your final test statistic to 2 decimals