Question 970788
The playing life of a Euclid MP3 player is normally distributed with a mean if 30,000 hours and a standard deviation of 500 hours. Matts MP3 player lasted for 31,500 hours. His MP3 Player lasted longer than what percent of other Euclid MP3 players?
1)68%. 2)95%. 3)99.7%. 4)more than 99.8% 

Solution:
z score ={{{(31500-30000)/500 = 3}}}
P(Z < 3) =  0.9987 [4 decimal places]
Therefore, the answer is 4)more than 99.8%