Based on a Random Sample of 13 Tire Changes, the Mean

question 108

Multiple Choice

Based on a random sample of 13 tire changes, the mean time to change a tire on a Boeing 777 has a mean of 59.5 minutes with a standard deviation of 8.4 minutes. For 10 tire changes on a Boeing 787, the mean time was 64.3 minutes with a standard deviation of 12.4 minutes. To test for equal variances in a two-tailed test at α = .10, the critical values are:

• A)3.73 and 0.228
• B)2.51 and 3.67
• C)3.07 and 0.398
• D)3.07 and 0.357

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Definitions:

Weighted-Average Method

A method of inventory costing that assigns a weighted average cost to each item in inventory, used in both perpetual and periodic inventory systems.

Process Costing System

A costing methodology used in manufacturing where costs are assigned to batches of products rather than individual items, suitable for homogeneous products.

Equivalent Units

The product of the number of partially completed units and their percentage of completion with respect to a particular cost. Equivalent units are the number of complete whole units that could be obtained from the materials and effort contained in partially completed units.

Conversion Costs

The combined costs of direct labor and manufacturing overheads, representing the costs to convert materials into finished goods.