Awwm01.bcc.cuny.edu C (17 points) Periodically, the county Water Department tests the drinking water of homeowners for contaminants such as lead and copper. The lead levels in water specimens collected in 1998 for a sample of 5 residents of a subdevelopement of the county is shown below. lead ( / g/L) 4.5 1.6 5.3 3.4 3.3 (a) Fill in the following chart to determine the sample mean T and sample standard deviation, S. 4.5 1.6 5.3 3.4 3.3 Then, n S =1 n-1 (b) Determine the critical value, t.go. t.90 = (c) Determine the maximal margin of error. E = (d) Construct a 99% confidence interval for the mean lead level in water specimans of the subdevelopment.