The mean lifespan of a track athlete is 53 years. If the standard deviation 12 years with the age normally distribute:
a. What is the probability that a randomly selected track athlete will live more than 65 years?
b. Random samples of 10 track athletes are taken with a mean age of x . Is the shape of the sampling distribution of x approximately normal why or why not.
c. Calculate the probability that a random sample of 10 track athletes will have a mean life span of 65 or above.
d. Why are the answers different in parts a. and c.?