A manufacturer knows that their items have a normally distributed lifespan, with a mean of 7.5 years, and a standard deviation of 0.5 years.  If you randomly purchase one item, what is the probability it will last longer than 9 years? Write your answer as a decimal using the appropriate rounding rul

A manufacturer knows that their items have a normally distributed lifespan, with a mean of 7.5 years, and a standard deviation of 0.5 years.  If you randomly purchase one item, what is the probability it will last longer than 9 years? Write your answer as a decimal using the appropriate rounding rule.