NARRBEGIN: Tire Rotation
Tire Rotation
the Manager of a Service $\bar { x }$

question 55

Essay

NARRBEGIN: Tire Rotation
Tire Rotation
The manager of a service station is in the process of analyzing the number of times car owners rotate the tires on their cars. She believes that the average motorist rotates his or her car's tires less frequently than recommended by the owner's manual (two times per year). In a preliminary survey she asked 14 car owners how many times they rotated their cars' tires in the last 12 months. The results are 1, 1, 2, 0, 3, 3, 0, 1, 0, 1, 2, 3, 3, and 1.NARREND
-The air pumps at service stations come equipped with a gauge to regulate the air pressure of tires. A mechanic believes that the gauges are in error by at least 3 pounds per square inch. To test his belief he takes a random example of 50 air pump gauges and determines the difference between the true pressure (as measured by an accurate measuring device) and the pressure shown on the air pump gauge. The mean and the standard deviation of the sample are $\bar { x }$ = 3.4 and s = 1.2. Can the mechanic infer that he is correct at the 5% significance level? Assume tire pressures have a normal distribution.

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Definitions:

Nonexcludable

A characteristic of a good or service that prevents people from being excluded from using it, often leading to challenges in private market provision.

Rival In Consumption

Goods or services that cannot be enjoyed by more than one person at the same time, as the consumption by one prevents that by another.

Common Resource

A resource like air or water that is not owned by anyone, but available for use by everyone, often leading to overuse and depletion.

Common Resources

Goods that are non-excludable and rival in consumption, such as fisheries, forests, and the atmosphere, which are accessible to all but can be depleted by overuse.