What I Know Choose the letter of the correct answer. 1. A quantity resulting from an experiment by chance that can assume different values is called ________________. A. Random sample B. Random variable C. Random process D. Random experiment 2. Which of the following is NOT a true statement? A. Random variables can only have one value. B. The value of a random variable could be zero. C. The probability of all the value of a random variable could be zero. D. The sum of all the probabilities in a probability distribution is always equal to one. 3. If a coin is tossed, what are the possible values of the random variable for the number of heads? A. 0, 1 B. 0, 1, 2 C. 1, 2, 3 D. 0, 1, 2, 3 For numbers 4 - 9. Suppose you tossed two coins. 4. What are the sample spaces for the experiment above? A. HH, TT B. HH, HT, TT C. HH, TH, TT D. HH, HT, TT, TH 5. How many possible outcomes will occur from the experiment above? A. 2 B. 3 C. 4 D. 5 6. What are the possible values of the random variable for the number of heads? A. 0, 1 B. 0, 1, 2 C. 1, 2, 3 D. 0, 1, 2, 3 7. What are the possible values of the random variable for the number of tails? A. 0, 1 B. 0, 1, 2 C. 1, 2, 3 D. 0, 1, 2, 3 8. Which of the following is NOT a possible value of the random variable for the number of heads? A. 1 B. 2 C. 3 D. 4 9. Which of the following is NOT a possible value of the random variable for the number of tails? A. 4 B. 3 C. 2 D. 1 For numbers 10 - 11. You decide to conduct a survey of families with two children. You are interested in counting the number of girls (out of 2 children) in each family. 10. Is the above experiment "counting the number of girls (out of 2 children in each family" a random variable? A. Yes, it is a random variable. B. No, it is not a random variable. C. Maybe. D. It cannot be determined. 11. If the experiment above shows a random variable, then what are the possible values of it? A. Its value can be 1 or 2. B. Its value can be 0, 1, or 2. C. Its value can be 2 or 4. D. None, since it is not a random variable. 12. In a local community, a couple was asked the questions, "Are you satisfied with the work of the current president?" If the husband and the wife both said "yes", the response is written as YY. If the husband said yes and the wife said "no", the response is YN. Let X be the number of "yes" responses, what are the possible values of the random variables? A. 0, 1, 2 B. 1, 2, 3 C. 2, 3, 4 D. 1, 1, 2 For numbers 13 - 15. Suppose two laptops are tested. Let D represent the defective laptop and N represent the non-defective laptop. 13. What are the possible sample spaces for the experiment? A. DD, NN B. DD, DN, NN C. DD, ND, NN D. DD, DN, NN, ND 14. How many possible outcomes will occur from the experiment? A. 2 B. 3 C. 4 D. 5 15. If we let X be the random variable representing the number of defectivelaptops. What are the possible values of the random variable? A. 0, 1 B. 0, 1, 2 C. 1, 2, 3 D. 0, 1, 2, 3