Answer:
2.35%
Explanation:
First, calculate the difference between mean and the months in the problem:
first month :59 – 26 = 33
second motnh: 59 – 37 = 22
Since standard deviation is 11 months, for the first month is a difference of 3 standard deviation and for the second is 2 standard deviation.
the 68-95-99.7% rule establish that:
1 standard deviation means a 68% of total area under the normal distribution. On one side is half = 34%.
2 standard deviations means a 95% of total area under the normal distribution. On one side is half = 47.5%.
3 standard deviation means a 99.7% of total area under the normal distribution. On one side is half = 49.85%.
The difference between 3 and 2 standard deviation is
49.85 – 47.5 = 2.35%
The answer is 2.35% of cars that remain in service between 26 and 37 months