SOLUTION: Company XYZ knows that replacement times for the portable MP3 players it produces are normally distributed with a mean of 4 years and a standard deviation of 0.6 years.
Find the
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Question 1135693: Company XYZ knows that replacement times for the portable MP3 players it produces are normally distributed with a mean of 4 years and a standard deviation of 0.6 years.
Find the probability that a randomly selected portable MP3 player will have a replacement time less than 2.3 years? P(X<2.3 years) = ____
Answer accurately to 4 decimals. Answers obtained using exact z-scores or z-scores rounded to 3 decimals places are accepted.
If the company wants to provide a warranty so that only 3% of the MP3 players will be replaced before the warranty expires, what is the time length of the warranty? Warranty = ___ years
Answer accurately to 1 decimal. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted. Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! z=(x-mean)/sd
for x<2.3 years, z<=-1.7/0.6=-2.833
This probability is 0.0023
z-score for 0.03 is -1.881
-1.881=(x-4)/0.6
x=2.871 years
