Let X denote the distance (m) that an animal moves from its birth site to the first territorial vacancy it encounters. Suppose that for banner- tailed kangaroo rats, X has an exponential distri- bution with parameter l 14 .01386 (as suggested in the article "Competition and Dispersal from Multiple Nests," Ecology, 1997: 873-883).

a. What is the probability that the distance is at most 100 m? At most 200 m? Between 100 and 200 m?

b. What is the probability that distance exceeds the mean distance by more than 2 standard deviations?

c. What is the value of the median distance?