model_random_forrest_optimal <- randomForest(INCOME ~ ., 
data = TrainSet,
ntree = 500, mtry = 3, 
importance = TRUE)

model_decision_RF = predict(model_random_forrest_optimal, data = TrainSet)
table(model_decision_RF, TrainSet$INCOME)
mean(model_decision_RF == TrainSet$INCOME)

#[1] 0.7757143