A Manufacturer Claims That the Mean Lifetime of Its Lithium

question 39

Essay

A manufacturer claims that the mean lifetime of its lithium batteries is 1400 hours. A homeowner selects 25 ofthese batteries and finds the mean lifetime to be 1380 hours with a standard deviation of 80 hours. Test themanufacturerʹs claim. Use α = 0.05. Round the test statistic to the nearest thousandth.

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Definitions:

Available-For-Sale Securities

Financial assets that are neither held for trading purposes nor intended to be held to maturity, which can be sold in the short-term.

Trading Securities

Financial instruments bought and held primarily for selling them in the near term to profit from short-term price fluctuations.

Fair Value

An estimate of the market value of an asset or liability, based on the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants.

Equity Method

An accounting technique used to record investments in associate companies, reflecting the investor’s share of the investee’s profit or loss.