A manufacturer claims that in a process of producing kitchen knives, only 2.5% of the knives are

Question:

A manufacturer claims that in a process of producing kitchen knives, only 2.5% of the knives are dull. Test the claim against the alternative that more than 2.5% of the knives are dull, using a sample of 400 knives containing 17 dull ones, (Use a = 5%).