(a) A manufacturer claims that the mean lifetime of its fluorescent bulbs is 1000 hours. A homeowner wonders if the actual mean lifetime of bulbs is different from 1000 hours. The homeowner selects 40 bulbs and finds the mean lifetime to be 990 hours with a standard deviation of s = 80 hours. Test the manufacturer’s claim. Use the critical value method and α = 0.05. (b) You work for a consumer advocate agency and want to find the mean lifetime of fluorescent bulbs. You randomly select 40 bulbs and find that the mean lifetime of these bulbs is 990 hours with a standard deviation of s = 80 hours. Calculate a 95% confidence interval for the population mean lifetime. (c) Explain how the above two statistical procedures lead to the same conclusion.
(a) A manufacturer claims that the
A homeowner wonders if the actual mean lifetime of bulbs is different from 1000
hours. The homeowner selects 40 bulbs and finds the mean lifetime to be 990 hours
with a standard deviation of s = 80 hours. Test the manufacturer’s claim. Use the
critical value method and α = 0.05.
(b) You work for a consumer advocate agency and want to find the mean lifetime of
fluorescent bulbs. You randomly select 40 bulbs and find that the mean lifetime of
these bulbs is 990 hours with a standard deviation of s = 80 hours. Calculate a
95% confidence interval for the population mean lifetime.
(c) Explain how the above two statistical procedures lead to the same conclusion.
Trending now
This is a popular solution!
Step by step
Solved in 3 steps with 2 images
