The advertised claim for batteries for cell phones is set at 48 operating hours with proper charging procedures. A study of 5500 batteries is carried out and 20 stop operating prior to 48 hours. Do these experimental results support the claim that less than 0.25 percent of the company's batteries will fail during the advertised time period, with proper charging procedures? (a) Use a hypothesis-testing procedure with = 0.05. What is the P-value? (b) Explain how you could answer the question in Part (a) by constructing a 95% one-sided confidence interval on p.