TABLE 10-8
a Buyer for a Manufacturing Plant Suspects

question 136

Short Answer

TABLE 10-8
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. The data collected is presented in the table below, with some summary statistics presented (all of these might not be necessary to answer the questions which follow). The buyer believes that the differences are normally distributed and will use this sample to perform an appropriate test at a level of significance of 0.01.
$\begin{array}{crrr}&\text { Primary}&\text { Secondary }\\\underline{\text {Material }}&\underline{\text {Supplier}}&\underline{\text { Supplier }}&\underline{\text {Difference }}\\1 & \$ 55 & \$ 45 & \$ 10 \\2 & \$ 48 & \$ 47 & \$ 1 \\3 & \$ 31 & \$ 32 & -\$ 1 \\4 & \$ 83 & \$ 77 & \$ 6 \\5 & \$ 37 & \$ 37 & \$ 0 \\6 & \$ 55 & \$ 54 & \$ 1 \\\hline \text { Sum: } & \$ 309 & \$ 292 & \$ 17\\\text { Sum of Squares: } &\$ 17,573& \$ 15,472 &\$ 139\end{array}$




-Referring to Table 10-8, the decision rule is to reject the null hypothesis if _______.

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Definitions:

Sealed Trailer

A type of trailer designed to be completely closed off from external elements, often used for the transportation of goods that require protection from the environment.

Semi-Trailer Dump Box

A type of dump truck where the dump box is supported at the rear by its own axles and at the front by a detachable tractor unit.

Cubic Capacity

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Milk Tanker Trailer

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