Z- TESTS HYPOTHESIS TESTING OF PROPORTIONS

1A. A long-distance phone provider claims that 40% or less of all households use its service. A random sample of 200 households shows 95 use the service. Test the validity of the claim at a 0.02 significance level. Show the P-value as well.

1B. According to the human resources director of a plant, no more than 5% of employees hired in the past year have violated their pre-employment agreement not to use any of the illegal drugs. The agreement specified that random urine checks could be carried out to ascertain compliance. In a random sample of 400 employees, screening detected at least one of these drugs in the systems of 8% of those tested. At the 0.025 level, is the human resources director's claim credible? Determine and interpret the P-value for the test.