Normal Distribution

Question

Company XYZ know that replacement times for the DVD players it produces are normally distributed with a mean of 9.8 years and a standard deviation of 2.3 years.

If the company wants to provide a warranty so that only 2.7% of the DVD players will be replaced before the warranty expires, what is the time length of the warranty?

Answer 1

Look up in a table or use technology to find z = 1.93 corresponding to 97.3% being below this z value in a normal distribution.

Now solve for x in z = (x-µ)/σ and sub in z from above and μ and σ that were given.

Consider a tutor, please!