Researchers at the Mayo Clinic have studied the effect of sound levels on patient healing and have found a significant association (louder hospital ambient sound level is associated with slower postsurgical healing). Based on the Mayo Clinic's experience, Ardmore Hospital installed a new vinyi flooring that is supposed to reduce the mean sound level (decibels) in the hospital corridors. The sound level is measured at five randomly selected times in the main corridor. TT New Flooring old Flooring 37 53 38 45 45 48 39 50 44 49 Click here for the Excel Data File (a-1) Does the evidence convince you that the mean sound level has been reduced? Select the appropriate hypotheses. a. Hg P1- 42 20 v. H: P1-P2 9.60 or Fcalc 1042. (df1 = 4, d.f2= 4) (b-3) What is the test statistic? (Round the test statistic value to 4 decimal places.) Test statistic (b-4) At a = 05, has the variance changed? He, the variance been changed.