Sphygmomanometers An aneroid sphygmomanometer is a mechanical device used to measure blood pressure. A random sample of these devices is tested for accuracy and the errors

(mm Hg) are listed below (based on data from “How Accurate Are Sphygmomanometers?”

by Mion and Pierin, Journal of Human Hypertension, Vol. 12, No. 4). One of the devices is considered to be unacceptable if its error is more than 3 mm Hg. We will use this criterion for concluding that the sample is from a population of unacceptable devices: s 7 1.5 mm Hg. Use a 0.05 significance level with the sample data to test the claim that the sample is from a population with a standard deviation greater than 1.5 mm Hg. What does the result suggest about the accuracy of aneroid sphygmomanometers?

-4 -11 5 5 8 14 -16 -12 4 6 -6