Self-Service Checkout Sales Employee Operated Checkout Sales Mean 36,709.11 46,995.93 Variance 56,649,037.54 401,208,905.56 Observations 180.00 180.00 Pooled Variance 228,928,971.55 Hypothesized Mean Difference 0 df 358 t Stat -6.44988 P(T<=t) one-tail 0.00000 t Critical one-tail 1.64912 P(T<=t) two-tail 0.00000 t Critical two-tail 1.96661 Is there is a statistical difference between the variables