A K-Brown medical symptom checklist is designed to reflect the sleep status of an individual.Individuals evaluated as having mildly unhealthy states of sleepare known to have a mean K-Brown score of 40.A group of 28 randomly selected individuals who exhibited scores of 40 participated in a 3 month structured meditation program, followed by a one month evaluation of their sleep using the K-Brown checklist.The mean scores from this group were:x-bar = 48.83 and s = 20.76 .The program administrator is interested to know if the results of the meditation program increases the K-Brown score, to a degree that is statistically significant.A level of = .05 is chosen as the level of significance for the hypothesis test.

What is the test statistic?