SOLUTION: The lifetime of a certain brand of electric light bulb is known to have a standard deviation of 47 hours. Suppose that a random sample of 50 bulbs of this brand has a mean lifetime
Algebra ->
Probability-and-statistics
-> SOLUTION: The lifetime of a certain brand of electric light bulb is known to have a standard deviation of 47 hours. Suppose that a random sample of 50 bulbs of this brand has a mean lifetime
Log On
Question 314218: The lifetime of a certain brand of electric light bulb is known to have a standard deviation of 47 hours. Suppose that a random sample of 50 bulbs of this brand has a mean lifetime of 485 hours. Find a 90% confidence interval for the true mean lifetime of all light bulbs of this brand. Then complete the table below.
Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place.
What is the lower limit of the 90% confidence interval?
What is the upper limit of the 90% confidence interval? Answer by quikralo(1) (Show Source):
(