The Quality Control Manager of a Major Cell Phone Provider

question 78

Multiple Choice

The quality control manager of a major cell phone provider is concerned about the life of the cell phone batteries they use. He took a sample of 13 batteries from a recent shipment and used them continuously until they failed to work. The manager measured the number of hours the batteries lasted and found the mean to be 550.4 with a standard deviation of 315.3.
-The null and alternative hypotheses to provide evidence that the mean life of the batteries is more than 400 hours is _____.

• A)H₀: ? = 400 vs.H_a: ? ? 400
• B)H₀: ? ? 400 vs.H_a: ? < 400
• C)H₀: ? ? 550.4 vs.H_a: ? < 550.4
• D)H₀: ? ? 400 vs.H_a: ? = 400
• E)H₀: ? ? 400 vs.H_a: ? > 400

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Definitions:

Unsecured Debts

Obligations for which the borrower does not provide collateral, making them riskier for lenders.

Involuntary Bankruptcy

A legal procedure where creditors petition a court to declare a debtor bankrupt, without the debtor’s consent, in order to recoup some of the owed money.

Chapter 13

A type of bankruptcy filing in the United States that allows individuals earning a regular income to develop a plan to repay all or part of their debts over time.

Steady Income

A consistent flow of money earned or received over time, usually through employment, investments, or other reliable sources.