The yields from catalytic reactors depend on the catalyst. For one series of tests the yield was measured for two catalysts, X and Y. Nine measurements of yield were measured with catalyst X and 6 with catalyst Y X: 1.74, 1.62, 1.59, 1.70, 1.73, 1.60, 1.56, 1.66, 1.71 Y: 1.46, 1.53, 1.49, 1.45, 1.51, 1.50 Is there a significant difference in yields?