A Buyer for a Manufacturing Plant Suspects That His Primary

Multiple Choice

A buyer for a manufacturing plant suspects that his primary supplier of raw materials is overcharging. In order to determine if his suspicion is correct, he contacts a second supplier and asks for the prices on various identical materials. He wants to compare these prices with those of his primary supplier. He collected data on 6 different materials from both suppliers. He believes that the differences are normally distributed. Which of the following tests will be the most appropriate?

A) Wilcoxon signed rank test
B) Wilcoxon rank sum test
C) pooled-variance t test
D) paired t test