In the following probability distribution, the random variable X represents the number of activities a parent of a 6th- to 8th-grade student is involved in.
x .... P(x)
0 .... 0.073
1 .... 0.117
2 .... 0.258
3 .... 0.322
4 .... 0.230
(a) Verify that this is a discrete probability distribution.
(b) Draw a probability histogram.
(c) Compute and interpret the mean of the random variable X.
(d) Compute the standard deviation of the random variable X.
(e) What is the probability that a randomly selected student has a parent involved in three activities?
(f ) What is the probability that a randomly selected student has a parent involved in three or four activities?