Question

Company XYZ know that replacement times for the DVD players it produces are normally distributed with a mean of 10 years and a standard deviation of 1.7 years. Find the probability that a randomly selected DVD player will have a replacement time less than 5.2 years? P(X < 5.2 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 1.1% of the DVD players will be replaced before the warranty expires, what is the time length of the warranty? warranty = years

Answer 1

µ = 10

sd = 1.7

a)

                              

                               = P(Z < -2.824)

                               = 0.0024

b)

or, x = 10 - 2.29 * 1.7

or, x = 6.107 years or 6 years (approx)