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.Com
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): You can put this solution on YOUR website!
RELATED QUESTIONS
The lifetime of a certain brand of battery is known to have a standard deviation of... (answered by stanbon)
The lifetime of a certain brand of battery is known to have a standard deviation of 23... (answered by stanbon)
The lifetime of a certain brand of battery is known to have a standard deviation of 16... (answered by stanbon)
The lifetime of a certain brand of battery is known to have a standard deviation of 10.5... (answered by stanbon)
The lifetime in hours of a brand of light bulb is normally distributed with a mean of 221 (answered by Theo)
Confidence interval for the population mean: Use of the standard normal
The lifetime... (answered by stanbon)
The lifetime of a certain brand of battery is known to have a standard deviation 16 of... (answered by 1satanist)
Can someone please help me solve this and explain why? Thank you
The lifetime of a... (answered by stanbon)
The lifetimes of a certain brand of light bulbs are known to be normally distributed with (answered by ewatrrr)