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Company XYZ know that replacement times for the quartz time pieces it produces are normally distributed with a mean of 17.4 years and a standard deviation of 2 years. Find the probability that a randomly selected quartz time piece will have a replacement time less than 13.4 years? P(X < 13.4 years) = Enter your answer accurate to 4 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.
Company XYZ know that replacement times for the DVD players it produces are normally distributed with a mean of 4.6 years and a standard deviation of 1.5 years. If the company wants to provide a warranty so that only 2.4% of the DVD players will be replaced before the warranty expires, what is the time length of the warranty? warranty = years Enter your answer as a number accurate to 1 decimal place. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.