The lifetime (in hours)of a 60-watt light bulb is a random variable that has a Normal distribution with$\sigma$= 30 hours.A random sample of 25 bulbs put on test produced a sample mean lifetime of = 1038.What is the 92% confidence interval estimate for the mean lifetime $\mu$?
A)(1022.1,1053.9).
B)(1027.5,1048.5).
C)(1026.2,1049.8).
D)(1028.1,1047.9).
E)(1022.5,1053.5).

Question

The lifetime (in hours)of a 60-watt light bulb is a random variable that has a Normal distribution with$\sigma$= 30 hours.A random sample of 25 bulbs put on test produced a sample mean lifetime of  = 1038.What is the 92% confidence interval estimate for the mean lifetime $\mu$?
A)(1022.1,1053.9). 
B)(1027.5,1048.5). 
C)(1026.2,1049.8). 
D)(1028.1,1047.9). 
E)(1022.5,1053.5).

Quizplus · Accepted Answer

The Answer of The lifetime (in hours)of a 60-watt light bulb is a random variable that has a Normal distribution with$\sigma$= 30 hours.A random sample of 25 bulbs put on test produced a sample mean lifetime of  = 1038.What is the 92% confidence interval estimate for the mean lifetime $\mu$?
A)(1022.1,1053.9). 
B)(1027.5,1048.5). 
C)(1026.2,1049.8). 
D)(1028.1,1047.9). 
E)(1022.5,1053.5).

The Lifetime (In Hours)of a 60-Watt Light Bulb Is a Random