18. Lead in Medicine Listed below are the lead concentrations (in ug/g) measured in dif- ferent Ayurveda medicines. Ayurveda is a traditional medical system commonly used in India. The lead concentrations listed here are from medicines manufactured in the United States. The data are based on the article "Lead, Mercury, and Arsenic in US and Indian Manufactured Ayurvedic Medicines Sold via the Internet," by Saper et al., Journal of the American Medical Association, Vol. 300, No. 8. Use the sample data to construct a 95% confidence interval esti- mate of the mean of the lead concentrations for the population of all such medicines. If a safety standard requires lead concentrations less than 7 ugg, does it appear that the population mean is less than that level? 3.0 6.5 6.0 5.5 20.5 7.5 12.0 20.5 11.5 17.5