Posted by Karen on Wednesday, September 2, 2009 at 3:50pm.
The lifetime of a 2volt nonrechargeable battery in contant use has a normal distribution with a mean of 516 hours and a standard deviation of 20 hours. Ninety percent of all batteries have a lifetime less than ?

Statistics  bobpursley, Wednesday, September 2, 2009 at 4:13pm
see the other post.

Statistics  Anonymous, Monday, January 30, 2012 at 8:33pm
541.6