Which statement is true regarding variance and standard deviation? (a) Variance equals twice the value of standard deviation. (b) Variance equals half the value of standard deviation. (c) Standard deviation is the square root of variance. (d) Standard deviation and variance are always equal. 2. Which of the following measurements is always included in the calculation of the variance? (a) mode (b) median (c) mean (d) range 3. Which statement is true regarding the variance of a set of numbers ? (a) If every number in a set is equal, the variance will equal zero . (b) A large value of variance means the numbers in a given set are close together. (c) A small value of variance means the numbers in a given set are far apart. (d) If every number in a set is equal, the variance can't be calculated. 4. Which statement is true regarding the calculation of (X - Xbar ) for variance ? (a) If the value of (X - Xbar ) is positive, then the given score equals the mean. (b) If the value of (X - Xbar ) is negative, then the given score equals the mean. (c) If the value of (X - Xbar ) is positive, then the given score lies below the mean. (d) If the value of (X - Xbar ) is negative, then the given score lies below the mean. 5. Which statement is true regarding the calculation of (X - Xbar )2 for variance ? (a) The value of (X - Xbar )2 is positive unless a given score equals the mean. (b) The value of (X - Xbar )2 is positive regardless of the score. (c) The value of (X - Xbar )2 is negative if a given score is below the mean. (d) The value of (X - Xbar )2 only equals zero if the given score equals zero. 6. Which statement about (X - Xbar )2 is true if the mean of set of numbers is 50, and a given score is 60 ? (a) The value of (X - Xbar )2 equals 10. (b) The value of (X - Xbar )2 equals 100. (c) The value of (X - Xbar )2 equals -10. (d) The value of (X - Xbar )2 equals 110