Need clarification on instructions

I am working on the cap-sleeve top in the "Crochet that Fits" by Mary Jane Hall, the directions for the sleeves are a bit confusing. I get really confused on row 3, below are the instructions.

Ch 41

Row 1: (RS) Dc in 4th ch from hook, dc in each rem ch across; turn - 39 dc (got this part)

Row 2: Ch 3, sk first dc, dc in blo of each dc across, ending with last dc in first skipped ch; turn - 39 dc (got this part too)

Row 3: Work same as Row 2, ending with last dc in 3rd ch of beg ch-3 (confused where to stop)

Row 4-10: Rep Row 3, 7 times more. End after last row. (not a clue what it means)

What confuses me is that is doesn't tell me how many stiches there are in row 3. Does it mean that I need to shorten every row on one side and not the other? If someone knows the answer please let me know I really want to finish this sweater it is so pretty.