4-32. The cumulative distribution function for a continuous random variable X is F(t) = -1 et/ , > 0, t 0; 0

4-32. The cumulative distribution function for a continuous random variable X is F(t) = -1 − e−t/θ , θ > 0, t ≥ 0;

0 t < 0.

Demonstrate that θ is the mean of X.