As long as your initial calculation was correct, then your dilutions seem OK.
Your last dilution is incorrect, however.
To 200 mL of 5 dkH, adding 40 mL of distilled water will yield 240 mL of 4.16 dkH reference solution, not a solution of 4 dkH.
200 / 5 = 40 per 1 dKH.
What am I forgetting?