Company XYZ know that replacement times for the quartz time pieces it produces are normally distributed with a mean of 17.8 years and a standard deviation of 1.3 years. If the company wants to provide a warranty so that only 2% of the quartz time pieces 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.