A study was conducted to investigate risk factors for the development of thrombosis. One outcome of interest was anticardiolipin antibody levels. The following data was obtained from samples of individuals with and without thrombosis. Group Mean anticardiolipin Standard Sample antibody level deviation Size Thrombosis 59.05 48.24 105 No Thrombosis 47.21 46.45 206 In the following questions, assuming equal population variances, test the claim that there is a difference in mean antibody level between individuals with thrombosis vs. individuals without thrombosis at 5% significance