K3 (inc in next st) 4 times means to Knit 3, then do increase in the next 4 sts. This will make 1 inc in each of the 4 sts with total of 4 increase, so you will end up with 8 sts total.
You can pick what method of increase you want.
So you knit 3 sts, (inc the next st), (inc the next st),( inc the next st),(inc the next st)
Here are the two ways of increase knitting I showed here in the video.