A Manufacturer Claims That the Mean Lifetime of Its Fluorescent $\alpha$

question 57

Essay

A manufacturer claims that the mean lifetime of its fluorescent bulbs is 1400 hours. A homeowner selects 25
bulbs and finds the mean lifetime to be 1390 hours with a standard deviation of 80 hours. Test the
manufacturerʹs claim. Use $\alpha$ = 0.05.

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Definitions:

Surplus

An excess of something, especially a quantity of a commodity or financial instrument that exceeds what is needed or used.

Equilibrium Price

The price at which the quantity of a good demanded equals the quantity supplied, leading to market balance.

Equilibrium Quantity

The amount of goods or services that is supplied and demanded at the equilibrium price.

Price Floor

A minimum price set by the government for certain goods and services, which cannot legally be lowered.