Suppose the average age of a passenger train car is 19.6 years. If the distribution of ages is normal and 15% of the cars are older than 21.0 years, find the standard deviation. Round final answer to two decimal places.
.5000-.1500=.3500=1.04
21.0=1.04(.87)+19.6
Is my answer (.87) right?
.5000-.1500=.3500=1.04
21.0=1.04(.87)+19.6
Is my answer (.87) right?
