Let X be a uniform random variable betweenaandb, wherea < b < 0. Please select all of the following statements that areTRUE.(There may be more than one correct answers)

a) X is not a valid uniform random variable becauseaandbcannot be negative.

b) In the rangea < x < b, the cumulative distribution function of X is the constant value 1/(b-a).

c) The mean value of X is (b-a)/2.

d) The probability that X is greater than its mean value is 0.5.