IQ test was administered to 5 person before and after they are trained.
Candidates: I II III IV V
IQ before training: 110 120 123 132 125
IQ after training: 120 118 125 136 121
Test whether there is any change in IQ after the training program. (The absolute value of t for 4 degrees of freedom at 1% level for one-tailed and two tailed tests are 3.747 and 4.604 respectively)