Suppose harvey owns a small business that produces electron microscopes. he previously owned one machine, machine a, that produced these microscopes. in an effort to increase production, he recently purchased a new machine, machine b, that also produces microscopes. although both machines produce microscopes at the same rate, harvey suspects that machine a produces more defective microscopes than machine b. in order to test this hypothesis, he randomly selects 300 microscopes produced by machine a and 280 microscopes produced by machine b. he observes that 18 of the sampled items from machine a are defective and 14 sampled items from machine b are defective. harvey plans to use the sample data he collected to test if the frequency of defective items produced by machine a is greater than the frequency of defective items produced by machine b. select the appropriate test that harvey should perform to test his hypothesis. matched-pairs ‑test two-sample ‑test for two proportions one-sample ‑test for a mean two-sample ‑test for two means one-sample ‑test for a proportion