Related questions with answers
Refer to earlier exercise. The Sylvania CFL 65watt replacement bulbs that utilise only 16 watts are advertised as having an average lifespan of 8000 hours on their packaging. Assume that the average lifespan of each of these bulbs is 8000 hours, with a 400hour standard deviation. Determine the likelihood that a random sample of 25 of these bulbs will have a mean life of a. less than 7890 hours b. between 7850 and 7910 hours c. within 130 hours of the population mean d. less than the population mean by 150 hours or more
Solution
VerifiedRecall that for the sampling distribution of $\bar{x}$, in an earlier exercise we established the following:

the sampling distribution of $\bar{x}$ is normal

$\mu_{\bar{x}}=8000\text{ hours }$

$\displaystyle \sigma_{\bar x}=\frac{400}{\sqrt{25}}=80 \text{ hours }$
Create an account to view solutions
Create an account to view solutions
More related questions
 business math
 business math
 business math
 business math
 business math
 business math
1/4
 business math
 business math
 business math
 business math
 business math
 business math
1/7