1. What do you call a random variable with possible values that form a finite or countable set? A. continuous C. finite B. discrete D. infinite 2. What term is used to describe the average value of a discrete random variable over numerous trials of an experiment? A. mean C. standard deviation B. probability D. variance 3. Which of the following represents the amount of spread, dispersion, or variability of the items in a distribution? A. mean or expected value B. median and mode C. outcomes and probability distribution D. variance and standard deviation 4. Which of the following is also equal to the square root of the variance? A. mean C. probabilityB. median D. standard deviation to zero? 5. How would you interpret a very small variance or standard deviation but not equal A. The values of the random variables are farther from the mean. B. The values of the random variables are nearer to the mean. C. The values of the random variables are equal to the mean. D. The values of the random variables have no relationship with the mean. variability? 6. Which of the following shows most likely the largest possible variance or A. number of girls in a randomly selected three-child family B. number of newborn babies per minute. C. number of Oreo cookies inside a 133 grams pack from different branch of 711 stores D. number of patients who are positive with COVID-19 in different hospitals 7. Which of the following data shows most likely the smallest possible variance or variability? A. number of books in different branch of National Bookstore B. number of books inside a pack bag of grade 11 students C. number of books inside the library of different universities D. number of books inside the library of different households 8. What formula is described by 62 = _[x2P(x)] -uz? A. the mean of a discrete random variable B. the variance of a discrete random variable C. the standard deviation of a discrete random variable D. the expected value of a discrete random variable For numbers 9-12, refer to the probability distribution of rolling a single unfair die. x 1 2 3 4 5 6 P(x) 0.1 0.1 0:1 0.5 0.1 0. 1 9. What is the mean of the probability distribution? A. 2.5 B. 3.7 C. 4.1 D. 5.7 10. What is the variance of the probability distribution? A. 1.81 B. 2.34 C. 3.70 D. 4.26 11. What is the standard deviation of the probability distribution? A. 1.07 B. 1.35 C. 1.92 D. 2.06 12. How would you interpret the mean value that you get in item number 9? A. The mean value is the difference between each probable value of the outcome when you roll the unfair die in numerous trials. B. The mean value is the higher probable value of the outcome when you roll the unfair die in numerous trials. C. The mean value is the lowest probable value of the outcome when you roll the unfair die in numerous trials. D. The mean value is the closest value to the most probable value of the outcome when you roll the unfair die in numerous trials. 13. Which of the following is NOT a property of the variance? A. The variance is not equal to the standard deviation. B. A small variance means that the distribution of the random variable is narrowly concentrated around the mean. C. A large variance means that the distribution is spread out, with some chance of observing values at some distance from the mean. D. The value of the variance is less than zero.For numbers 14-15. The mean of the probability distribution below is equal to 18,2 with a variance of 5.86 and a standard deviation of 2.42. Number of cellphones sold per day in a retail store (x) 22 15 19 20 18 Probability (P(x) 0. 15 0.30 0.20 0.20 0. 15 14. How would you interpret the mean value of 18.2? A. B. The least number of cellphones that will be sold in a day is 18 pieces. The highest number of cellphones that will be sold in a day is 18 pieces. C. The average number of cellphones that will be sold in a day is 18 pieces. D. No interpretation can be made about the mean value of 18.2. 15. How would you interpret the values of variance and standard deviation? A. It gives the difference between the highest number of cellphones and the least number of cellphones that can be sold. B. It is the average number of cellphones that can be sold in a day. C. It describes how the data or the number of cellphones sold in a day varies. D. No interpretation can be made about the variance and standard deviation.Complete the following statements by writing the correct word or words. 1. The mean of a discrete random variable is interpreted as the value of a random variable over repeated trials of an experiment. 2. The variance and standard deviation of a discrete random variable measured or described the of the assumed values of the random variable to the mean. 3. A small variance or standard deviation means that the assumed values or data points tend to be to the mean. 4. A higher variance or standard deviation means that the assumed values or data points are from the mean
