A manufacturer claims that the mean lifetime of its fluorescent bulbs is 1000 hours. The lifetimes...

A manufacturer claims that the mean lifetime of its fluorescent bulbs is 1000 hours.
The lifetimes are normally distributed with a standard deviation of σ = 80 hours.

A homeowner decides to test the manufacturer's claim; in a random sample of 40 bulbs,
the mean lifetime is 980 hours.

At a significance level of α = 0.05, does this data provide evidence to reject the manufacturer's claim? Show all 7 steps for p-value method.

Solutions

Expert Solution

Solution-

Using information provided Z test is calculated to test the claim.

Test Results and calculation-

by above results the null hypothesis Ho is not rejected.

This data does NOT provide evidence to reject manufacturer's claim.

In other words-

we have enough evidence to support the manufacturer's claim that the mean lifetime of its fluorescent bulb is 1000 hours.

orchestra answered 1 year ago

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