1. A chemical plant which creates bleach claims an average daily yield of 880 tons per day. It is reasonable to suppose production levels are normally distributed-some days are slightly higher than others, some are lower. A random sample of 36 days yielded the average daily output of 890.2 tons, with the standard deviation of 19.8 tons. Use this information to make a 95% confidence interval for mean.
2. An ATM machine was installed at the Hunter Industries for exclusive use of Hunter's employees.
Union Bank wanted to determine the percentage of all employees which employed the machine at least twice in the last month. From a randomly selected sample of 100 employees, 45 did employ the ATM at least twice. Use this information to make a 95% confidence interval estimating the percentage of all employees that employ the machine at least twice per month.