Professor Sanchez has been teaching Principles of Economics for over 25 years. He uses the following scale for grading.

Grade	Numerical Score	Probability
A	4	0.120
B	3	0.240
C	2	0.370
D	1	0.145
F	0	0.125

Part (a) omitted

b.	Convert the above probability distribution to a cumulative probability distribution.(Round your answers to 3 decimal places.)

Grade	P(Xx)
F
D
C
B
A

c.	What is the probability of earning at least a B in Professor Sanchezs course?(Round your answer to 3 decimal places.)

Probability

d.	What is the probability that a student receives a D or better in the course?(Round your answer to 3 decimal places.)

Probability