# Question: suppose that random variable x represents the number of units...

###### Question details

Suppose that random variable X represents the number of units that college students register per semester. If X has the following probability mass function, what is the probability that a student registers three units or more per semester? x 1 2 3 4 5 P(x) 0.12 0.21 0.30 0.32 0.05

In reference to the probability mass function provided in Question 1, what it the standard deviation of X?

a. 1.100 b. 1.209 c. 3.167 d. 10.030