uestion 3 (6 marks)

Suppose that the random variable

x

has an exponential distribution with = 3.

Required:

a) Find the probability that

x

assumes a value more than three standard deviations

from .

(2 marks)

b) Find the probability that

x

assumes a value less than one standard deviation from

.

(2 marks)

c) Find the probability that

x

assumes a value within a half standard deviation of .

(2 marks)