Problem 2.1 Suppose a market research company is hired to estimate the percentage of adults who live in big cities that have PCs. 500 adult residents randomly selected in this city were surveyed to determine if they had a PC. Of the 500 people surveyed, 280 said yes, they have a PC. Using a 95 percent confidence level, calculate the estimated confidence interval for the actual proportion of adult residents in this city who have a PCs. Problem 3.3 Given the following hypothesis: Ho: H = 25 H1: u # 25 A random sample of 40 observations is selected from a normal population. The sample mean was 27 and the population standard deviation 18. Using the .05 significance level, what is the value of the test statistic