A new drug is developed for reducing the level of blood cholesterol. A sample of 10 people take this drug for two weeks. Their blood cholesterol are measured (in mg/dl) before and after the treatment. The data are as follows. Before 13.1 12.3 10.0 17.7 19.4 10.1 11.5 12.6 9.5 12.1 After 12.0 7.5 11.7 12.5 18.6 12.3 15.2 16.3 10.7 9.8 Let X, Y denote the level of blood cholesterol before and after the treatment respectively. Let E(X ) = /x and E(Y) = my. Do we have enough evidence to claim that the new drug is effective (i.e. (x > #y)