Question

Company XYZ know that replacement times for the DVD players it produces are normally distributed with a mean of 7.8 years and a standard deviation of 2.3 years.

Find the probability that a randomly selected DVD player will have a replacement time less than 3 years?
P(X < 3 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.

If the company wants to provide a warranty so that only 3.1% 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.

Answer 1