State University Uses Thousands of Fluorescent Light Bulbs Each Year $.05$

question 102

Essay

State University uses thousands of fluorescent light bulbs each year. The brand of bulb it currently uses has a mean life of 600 hours. A competitor claims that its bulbs, which cost the same as the brand the university currently uses, have a mean life of more than 600 hours. The university has decided to purchase the new brand if, when tested, the evidence supports the manufacturer's claim at the $.05$ significance level. Suppose 100 bulbs were tested with the following results: $\bar { x } = 627.5$ hours, $s = 100$ hours. Conduct the test using $\alpha = .05$ .

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Definitions:

Income Tax Rate

The percentage at which an individual or corporation is taxed; the rate may vary by income level, type of income, or other factors.

Working Capital

The distinction between a firm's current assets and its current liabilities, revealing the company's short-term financial health.

Straight-Line Depreciation

A method of allocating the cost of a tangible asset over its useful life in equal installments.

Incremental Sales

Additional sales generated by a new promotional strategy or marketing campaign, beyond the expected or normal sales volume.