A buyer for a manufacturing plant suspects that his primary supplier of raw materials is overcharging. To determine if his suspicion is correct, he contacts a second supplier and asks for the prices . He wants to compare these prices with those of his primary supplier: Primary Secondary Material Supplier Supplier Difference 1 $55 $45 $10 2 $48 $47 $1 3 $31 $32 -$1 4 $83 $77 $6 5 $37 $37 $0 6 $55 $50 $5 7 $47 $40 $7 mean: $4.00 standard deviation: $4.08 the hypotheses that the buyer should test are

We are given that a buyer for a manufacturing plant suspects that his primary supplier of raw materials is overcharging. To determine if his suspicion is correct, he contacts a second supplier and asks for the prices.

The data is given below;

Material Primary supplier Secondary supplier Difference

1 $55 $45 $10

2 $48 $47 $1

3 $31 $32 -$1

4 $83 $77 $6

5 $37 $37 $0

6 $55 $50 $5

7 $47 $40 $7

The hypothesis that the buyer should test is the paired t-test for the mean difference because we are interested in comparing the difference between the cost of raw materials charged by both the suppliers.