Researchers conducted an experiment in which hydrogen concentration in 20 different specimens was measured by gas chromatography and by a new sensor method. They want to test whether the two methods give essentially the same measurement.
(a) Explain why this is a matched pair/dependent sample experiment.
(b) Use the statistical summary for the difference of measurements to construct a 99% confidence interval for the mean difference between the two methods.
| Mean |
1.5 |
| Sample Standard Deviation |
6.661 |
| Sample Variance |
44.368 |
| Minimum |
-14 |
| Maximum |
13 |
| Count |
20 |
(c) Set up a test of the hypothesis that the mean difference between methods is 0. (State the null and alternate hypotheses.)
(d) Compute the observed value of the test statistic.
(e) Conduct the hypothesis test and state the decision and conclusion.