An instructor gives two students portions of the same ore sample to examine by gravimetric analysis. Student number 1 gets the following results for the iron content for this sample: 35.1, 33.8, and 34.5 mg/g. Student number 2 obtains values of 32.4, 33.1, and 32.7 mg/g. Are the mean results obtained by these two students the same at the 95% confidence interval? 3)

Construct a confidence interval for the mean of the paired differences for the two populations with the following information. Round the endpoints of the interval to three decimal places, if necessary. n=37n=37, d¯=2.191d¯=2.191, α=0.1α=0.1, sd=0.411sd=0.411

Arsenic is a compound that occurs naturally in very low concentrations. Arsenic blood concentrations in healthy individuals are Normally distributed with a mean of 3.2 mg/dl. Some areas of the United States have naturally elevated arsenic levels in the ground and water supplies. Researchers took a sample 20 water samples from a particular area and measured the arsenic levels in each of the 20 water samples. They want to determine if there is sufficient evidence to conclude that the arsenic level in that area is higher than 3.2 mg/dl. hypothesis test for one population mean (unknown population standard deviation) confidence interval estimate for one population mean (unknown population standard deviation) hypothesis test for population mean from paired differences confidence interval estimate for population mean from paired differences hypothesis test for difference in population means from two independent samples confidence interval estimate for difference in population means from two…

A group of students sampled water from 34 lakes in St. Joseph County. If the mean dissolvedoxygen level was 3.2 with a standard deviation of .57 find a 90% confidence interval for thedissolved oxygen levels in St Joseph County lakes.