The sample data table Chamber.jmp represents electrical measurements on 24 electrical boards. (This is the same data used in “Paired Means: The Wilcoxon Signed-Rank Test” on page 211.) Each measurement was taken when soldering was complete and then again three weeks later after sitting in a temperature- and humidity-controlled chamber. The investigator wants to know if there is a difference between the measurements.
(a) Why is this a situation that calls for a matched-pairs analysi?
(b) Using the paired t-test, determine if there is a significant difference between the means when the boards were outside versus. inside the chamber.
(c) Does the analysis in part (b) lead to the same conclusion as the Wilcoxon signed-rank test? Why or why not?