This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: 9 . 25 = x and a standard deviation 7 . 2 = s . a. Find a 95% confidence interval for the population mean . b. Find a 90% confidence interval for . c. Find a 99% confidence interval for . 4. Periodically, the Hillsborough County (Florida) Water Department tests the drinking water of homeowners for contaminants such as lead and copper. The lead and copper levels in water specimens collected for a sample of 10 residents of the Crystal Lakes Manors subdivision are shown in the next table. Lead (µg/L) Copper (mg/L) 1.32 .508 .279 13.1 .320 .919 .904 .657 .221 3.0 .283 1.32 .475 4.09 .130 4.45 .220 .743 1 a. Construct an 99% confidence interval for the mean lead level in water specimens from Crystal Lakes Manors. b. Construct an 99% confidence interval for the mean copper level in water specimens from Crystal Lakes Manors. 2...
View
Full Document
 Spring '11
 Gispy
 Standard Deviation, Crystal Lakes Manors

Click to edit the document details