1. The differences between covariance and correlation include A. Covariance is always in the range from minus -1 to positive 1 B. The formula for correlation does not include the standard deviations of the two variables C. The two statistics are always of opposite sign D. Covariance can be greater than one or less than minus -1 E. None of the above 2. Which of the following are true about Variance-Covariance matrices? A. They are always symmetric B. They show the variance and covariances for two or more random variables C. They show the means and skewness of the variables D. Both A and B E. None of the above 3. Which of the following are true about variance and standard deviation? A. Variance is always negative when the mean is negative B. Standard deviation is the square of the variance C. Variance is always greater than standard deviation D. Standard deviation is always negative E. None of the above 1. The differences between covariance and correlation include A. Covariance is always in the range from minus -1 to positive 1 B. The formula for correlation does not include the standard deviations of the two variables C. The two statistics are always of opposite sign D. Covariance can be greater than one or less than minus -1 E. None of the above 2. Which of the following are true about Variance-Covariance matrices? A. They are always symmetric B. They show the variance and covariances for two or more random variables C. They show the means and skewness of the variables D. Both A and B E. None of the above 3. Which of the following are true about variance and standard deviation? A. Variance is always negative when the mean is negative B. Standard deviation is the square of the variance C. Variance is always greater than standard deviation D. Standard deviation is always negative E. None of the above