A technician obtained the following results for the concentration (mg/dL) of cholesterol in a blood sample: 240, 252, 242, 238, 239, and 236. The technician re-measured the cholesterol in the same blood sample using a different method. The results were: 233, 231, 222, 235, 239, and 234.
a. At the 95% confidence level is the second method consistently less precise?
b. at the 95% confidence level does the second method give consistently lower results?