...confident that his error is less than t? In order to efficiently bid on a contact, a contractor wants to be 95% confident that his error is less than two hours in estimating the average time it takes to install tile flooring. Previous contracts indicate that the standard deviation is 4.5...
...deviation of 10.2. Consturct? A random sample of 40 students has a test score with a mean of 8.15 and standard deviation of 10.2. Construct the confidence interval for the population mean if c=0.90