turtle lifespan: mean of 180 yrs, st. dev. of 40 yrs

[Kiran]

The life spans of a particular species of turtle are normally distributed with a mean of 180 years and a standard deviation of 40 years. What proportion of these turtles will live between 100 and 260 years?

 

[stapel]

What are your thoughts? What have you tried? How far have you gotten? Where are you stuck?

Please be complete. Thank you!

Eliz.