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

question 95

Essay

A manufacturer claims that the mean lifetime of its fluorescent bulbs is 1500 hours. A homeowner selects 40
bulbs and finds the mean lifetime to be 1480 hours with a population standard deviation of 80 hours. Test the
manufacturerʹs claim. Use $\alpha$ = 0.05.

---

Definitions:

Confidence Interval

A collection of estimations, from sample-derived statistics, considered to likely house the unrevealed value of a population parameter.

Standard Deviation

A measure of the amount of variation or dispersion of a set of values, represented as the square root of the variance.

Population Mean

The mean of every number within a group.

Confidence Interval

A pool of values, from the statistical study of samples, presumed to envelop the covert figure of a population characteristic.