Question

A company manufactures light bulbs. The company wants the bulbs to have a mean life span of

999999

hours. This average is maintained by periodically testing random samples of

2525

light bulbs. If the t-value falls between

minus−t 0.95t0.95

and

t 0.95t0.95,

then the company will be satisfied that it is manufacturing acceptable light bulbs. For a random sample, the mean life span of the sample is

10061006

hours and the standard deviation is

2222

hours. Assume that life spans are approximately normally distributed. Is the company making acceptable light bulbs? Explain.

The company

is

making acceptable light bulbs because the t-value for the sample is

tequals=nothing

and

t 0.95t0.95equals=nothing.

(Round to two decimal places as needed.)

Answer #1

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