9.59 Washing Machine Colours A manufacturer of automatic washers provides a particular model in one of three colours. Of the first 1000 washers sold, it is noted that 400 were of the first colour. Can you con- clude that more than one-third of all customers have a preference for the first colour?

a. Find the p-value for the test.

b. If you plan to conduct your test using a = 0.05, what will be your test conclusions?