Probability Statistics
posted by Liza .
a manufacturing plant uses 3000 light bulbs whose lifetimes are independently normally distributed with mean 500 hrs, and standard deviation 50 hrs. to minimize the number of bulbs that burn out during production hours, all bulbs are replaced after given period of operation. how often should the bulbs be replaced if you want no more than 1% to burn out between replacements?
Should I just look up 1% under the zdistribution and find corresponding zscore to it, and with that find the Xvalue in hours?

Probability Statistics 
PsyDAG
Yes.
Respond to this Question
Similar Questions

Math
A consumer buys n light bulbs, each of which has a lifetime that has a mean of 800 hours, a standard deviation of 100 hours, and a normal distribution. A light bulb is replaced by another as soon as it burns out. Assuming independence … 
Math
A consumer buys n light bulbs, each of which has a lifetime that has a mean of 800 hours, a standard deviation of 100 hours, and a normal distribution. A light bulb is replaced by another as soon as it burns out. Assuming independence … 
probability and statistics
An electrical firm manufactures light bulbs that have a usuable life that is normally distributed with a mean of 1000 hours and a standard deviation of 80 hours. Find the probability that a package of 4 bulbs would last at least 4400 … 
Statistics 1
If light bulbs are normally distributed with a mean of 2500 hrs. and a standard deviation of 500 hrs. what percentage of light bulbs have a life span less than 2500 hrs.? 
sTATISTICS
If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, approximately what percentage of light bulbs has a life of more than 3000 hours? 
Ashworth college
The lifetimes of light bulbs of a particular type are normally distributed with a mean of 270 hours and a standard deviation of 11 hours. What percentage of the bulbs has lifetimes that lie within 2 standard deviations of the mean … 
Statistics
The lifetimes of projector bulbs of a particular type are normally distributed with a mean of 470 hours and a standard deviation of 15 hours. What percentage of the bulbs has lifetimes that lie within 2 standard deviations of the mean … 
Statistics
The lifetimes of projector bulbs of a particular type are normally distributed with a mean of 470 hours and a standard deviation of 15 hours. What percentage of the bulbs has lifetimes that lie within 2 standard deviations of the mean … 
statistics
The lifetimes of light bulbs of a particular type are normally distributed with a mean of 370 hours and a standard deviation of 5 hours. What percentage of bulbs has lifetimes that lie within 1 standard deviation of the mean on either … 
math
2) The lifetimes of light bulbs of a particular type are normally distributed with a mean of 370 hours and a standard deviation of 5 hours. What percentage of bulbs has lifetimes that lie within 1 standard deviation of the mean on …