Experimental Medication Placebo Characteristic (n=250) (n=250) Age, years: Mean (SD) 44.3 (1.4) 45.6 (3.1) % Males 55% 43% Education Level, years: Mean 13.1 (2.9) 14.2 (3.1) (SD) Annual Income, Dollars: $32,560 ($1,054) $34,470 ($998) Mean (SD) Body Mass Index, kg/m2: Mean 26.7 (4.0) 22.1 (6.4) SD) SD is the standard deviation of the variable listed. Question Calculate the test statistic for the difference in mean age in participants assigned to the experimental versus the placebo groups; assuming a = 0.05 and a pooled standard deviation of 2.41. 1.6 O 5.9 2.41 O -1.96 O -5.9