D Question 1 25 pts Find the mean of the random variable X with probability density function - x- = x on [-4, 0]. 0 -2 03 0 -1 D Question 2 25 pts Find the variance of the random variable X with probability density function -3 x2 - , x + 36 on [-5,1]. O T 0 -2 D Question 3 25 pts Probability distributions with small variances will often have more values closer to the mean than probability distributions with large variances. O True False Question 4 25 pts The expected value is always calculated using the variance. No. While the expected value is often calculated using the variance, the expected value may also be calculated using the standard deviation. No, the standard deviation is always calculated using the variance. The expected value is used to calculate the variance. Yes, the expected value is the square of the variance. Yes, the expected value is the square root of the variance. 18,453