Write the letter of the correct answer. Show your solution.
Multiple Choice. Read each statement carefully then WRITE your answers on the answer sheet. Show your Parent's Signature solution on the number that needs computation. DO NOT WRITE ANYTHING ON THE QUESTIONNAIRE. 1. Which of the following statement describes a continuous random variable? A. The number of learmers present in class Remulla B. The average distance travelled by a tricycle in a month C. The number of motorcycle owned by a randomly selected household D. The number of girls taller than 5 feet in a random sample of 6 girls 2. Which of the following is NOT a discrete variable? A. Number of books per student B. Number of green marbles in a box C. The number of arrivals of customers in a clinic at 8:00-5:00 D. The weight of a box of soft drinks labeled 12 ounces 3. Which of the following statements best describe the expected value of a discrete random variable? A. It is the simple average of all possible outcomes in the distribution B. It is the geometric average of all possible outcomes in the distribution C. It is the weighted average of all possible outcomes in the distribution D. It is the complex average of all possible outcomes in the distribution 4. Which of the following statement is true? A. A small value of standard deviation (or variance) indicates that the distribution of the random variable is concentrated narrowly around the mean B. A negative value of standard deviation (or variance) indicates that the distribution of the random variable s concentrated narrowly around the mean C. The values closer from Ux have equal probability D. The values closer from ux have different probability 5. You decided to order a pizza but you have to choose the type of crust and the toppings. If there are only 6 possible combinations of ordering a pizza, from which of the following should you choose? A. Crust: thick or thin Number: 2 - Week 2 Toppings: cheese or pepperoni B. Crust: thick or thin Toppings: cheese, bacon or pepperoni Lesson: Qualitative C. Crust: thick or thin Toppings: cheese, bacon, sausage or pepperoni D. Crust: thick or thin Toppings: cheese, bacon, sausage, hotdog or pepperoni 6. A drawer has 2 red ties, 3 black ties and 5 blue ties. A tie is picked at random. What is the total number of possible outcomes? A. 2 B. 3 C. 5 D. 10 7. What are the possible values of each random variable X if it represents the number of heads in tossing a coin thrice? A. X = {0, 1, 2, 3} B. X = {0, 1, 2} C. X = {1, 2, 3} D. X = {1, 2} 8. What are the values of P(X) if P(X) = */3, for X = 0, 1, 2 A. 0, 1, 2 B. 0, 0.45, 0.55 C. 0, 0.33, 0.67 D. 0.2, 0.3, 0.5 9. You decide to conduct a survey of families with two children. You are interested in counting the number of boys (out of 2 children) in each family. Is the experiment "counting the number of boys (out of 2 children) in each family" a random variable? A. yes B. no C. maybe D. cannot be determined 10. If the statement in number 10 shows a random variable, what are the possible values? A. 1 or 2 B. 0, 1 or 2 C. 2 or 4 D. none since it is a random variable 11. In the experiment of tossing a coin twice, the table shows the probability distribution. X 0 2 P(X) 0.25 5 0.50 0.25What is P(X52)? A. 0.25 B. 0.50 C. 0.75 D. 1.00 12. Referring to number 11, what is P(0) + P(2)? A. 1.00 B. 0.75 C. 0.50 D. 0.25 13. Which of the following is NOT a discrete random variable? A. Height of eggplant as measured each day B. Number of refrigerator sold each day C. Number of late comers going to school each day D. Number of people who went to Rizal Park during weekends 14. You decide to collect a bunch of cans of soda and measure the volume of soda in each can. Let X be the number of soda in each can. What type of variable is x? sure it A. X is a constant C. X is a discrete random variable B. X is a place holder D. X is a continuous random variable 15. Suppose two balls are drawn in succession without replacement from a box containing 6 blue balls and 5 red balls. How many possible outcomes will occur from the experiment? A. 2 B. 4 C. 6 D. 8 16. In her flower shop, Vera recorded the probability distribution for the number of flower arrangements that she delivered each day X 8 9 10 11 P ( X) 0 . 0.20 0.30 0.20 0.10 What is the probability that she made at least 9 flower arrangements? A. 0.60 B. 0.50 C. 0.40 D. 0.30 17. What is the mean of the given probability distribution? A. 8.50 B. 8.60 C. 8.70 D. 8.80 18. Which of the following is the appropriate value for the variance? A. 1.55 B. 1.56 C. 1.57 D. 1.58 19. Which of the following serve as the probability distribution of a random variable X? A. P(X) = 3+4, for X = 1, 2, 3, 4 B. P(X) = = , for X = 1, 2, 3, ... , 9 C. P(X) = = , for X = 1, 2, 3, ... , 8 D. P(X) = >, for X = 1, 2, 3 20. Two jars both contain the numbers 2, 4, 6, 8. The table shows the probability distribution of the sum when one number from each jar is taken at a time with replacement. X 4 6 8 10 2 14 16 P(X) 3 16 8 16 16 16 Find P(6) + P(8). A. - B. 76 C. 16 they mobach now D.T
