Calcium in Rainwater An environmentalist wants to determine if the median amount of

Chapter 15, Problem 13

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Calcium in Rainwater An environmentalist wants to determine if the median amount of calcium (mg/L) in rainwater in Lincoln County, Nebraska, is different from the median amount of calcium (milligrams per liter, mg/L) in the rainwater in Clarendon County, South Carolina. She randomly selects 22 weeks in which it rained at least once during the week in the Nebraska location and determines the calcium level of the rainwater. She obtains an independent random sample of 20 weeks in which it rained at least once during the week for the South Carolina location and determines the calcium level of the rainwater. Her data are shown in the following table: Lincoln County Calcium Level (mg/L) Clarendon County Calcium Level (mg/L) 0.11 0.41 0.19 0.33 0.06 0.12 0.14 0.10 0.09 0.33 0.67 0.20 0.09 0.29 0.14 0.21 0.21 0.20 0.75 0.42 0.14 0.10 0.12 0.16 0.09 0.22 0.19 0.25 0.16 0.41 0.08 0.13 0.07 0.34 0.30 0.47 0.03 0.08 0.09 0.12 0.30 0.46 Source: National Atmospheric Deposition Program Do the data indicate a difference in calcium levels at the a = 0.05 level of significance?