Using the cumulative distribution function for the discrete random variable X given below:

a. What is the probability that X = 45?
b. What is the probability mass function for X?
c. Is your answer to part b a valid probability mass function? Justify your answer.
d. What is the probability that X is between 25 and 50?
e. What is the probability that X is 70?
f. What is the probability that X is less than 70?
g. What is the probability that X is greater than 70?
h. What is the probability that X is between 60 and 70 (inclusive)?
i. What is the expected value of X?
j. What is the standard deviation of X?

Transcribed Image Text:

if <30, 0.2 if 30 Sa <45, 0.7 Fs (r) = if 4 5 sa <60, if60 r.