sTATISTICS
posted by KDIZZLE .
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?

Statistics 
Steve
well, 3000 is 1 std above the mean. So, check your Z table for the area of the tail above Z=1.
Or, play around at
http://davidmlane.com/hyperstat/z_table.html
Respond to this Question
Similar Questions

math
If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, what percentage of light bulbs have a life less than 2500 hours? 
statistics
If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, what percentage of light bulbs have a life less than 2500 hours? 
stats
If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, what percentage of light bulbs have a life less than 2500 hours? 
Statistics
If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, what percentage of light bulbs have a life less than 2500 hours 
Math
If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, what percentage of light bulbs have a life less than 2500 hours? 
Math
If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, use the 689599.7 rule to approximate the percentage of light bulbs having a life between 2000 hours and 3500 … 
Math
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? 
Math HELP!!!!!
If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, what percentage of light bulbs have a life less than 2500 hours? 
Math HELP!!!!!
light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, use the 689599.7 rule to approximate the percentage of light bulbs having a life between 2000 hours and 3500 hours? 
Math HELP!!!!!
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?