Posted by jamie on Monday, April 18, 2011 at 1:09am.
a light bulb manufacture gaurentees that the mean life of a certain type of bulb is at least 875 hours. A random sample of 40 light bulbs has a mean life of 863 hours with a standard deviation of 50. a=0.04

statistics(/)  PsyDAG, Monday, April 18, 2011 at 3:41pm
What is your question?

statitics  green, Sunday, October 11, 2015 at 2:53pm
Work: A random sample of 100 light bulbs has a mean lifetime of 3000 hours. Assume that the population standard deviation of the lifetime is 500 hours. Construct a 95% confidence interval estimate of the mean lifetime

statitics  Gladwin, Sunday, June 5, 2016 at 8:51pm
What
percentage of light bulb fail to satisfy to guarantee