Stat 200, Quiz #3 Name: Date: Chapters 4-5, 1. A graphical method of representing the sample points of an experiment is a. a frequency polygon b. a histogram c. an ogive d. a tree diagram ANS: 2. The range of probability is a. any value larger than zero b. any value between minus infinity to plus infinity c. zero to one d. any value between -1 to 1 ANS: 3. Events that have no sample points in common are a. independent events b. posterior events c. mutually exclusive events d. complements ANS: 4. If a six sided die is tossed two times and "3" shows up both times, the probability of "3" on the third trial is a. larger than any other outcome b. smaller than any other outcome c. 1/6 d. 1/216 ANS: 5. The counting rule that is used for counting the number of experimental outcomes when n objects are selected from a set of N objects where order of selection is important is called a. permutation b. combination c. multiple step experiment d. None of these alternatives is correct. ANS: 1 Stat 200, Quiz #3 Questions 6, 7 refer to Selecting a Card (Cards) from a standard deck of cards (keep in mind 52 cards all together, 4 of a kind like 4 kings, 4 queens, 4 jacks, also 26 black : 13 spades and 13 clubs, 26 red : 13 diamonds and 13 hearts) 6. a) If one card is selected randomly what is the probability of getting a black card? ANS: b) If one card is selected randomly what is the probability of getting a black card or a queen? ANS: 7. If two cards are selected in succession (means without replacement) what is the probability of selecting two red cards? ANS: For questions 8-9 consider: an experiment consists of rolling two six-sided dice and observing the face numbers. 8. Determine the probability that a) The sum of the numbers rolled is 4 b) The sum of the numbers rolled is not 4 Ans: 9. Determine the probability that a) A pair of sixes appear. b) Two different numbers appear. Ans: 1 2 Stat 200, Quiz #3 Questions 10, 11 refer to the following data: A bank has the following data on the gender and marital status of 200 customers. Single Married 10 Male Female 20 100 30 50 a) If one customer is selected at random, what is the probability of selecting a single male customer? b) If one customer is selected at random, what is the probability of selecting a male customer or a single customer? c) What is the probability of selecting a single customer, given that the customer is male? ANS: a) b) c) Chapter 5. 1. Determine whether the distribution represent a probability distribution. Explain your reasons. a) x is 1, 2, 3 and the corresponding probabilities are , and 3/8. 3 Stat 200, Quiz #3 b) ANS: a) b) 2. If a family plans 2 kids construct a probability distribution for the number of girls. Write the probabilities as simplified fractions. Number of girls X Probability P(X) 3. The probability distribution of the daily demand for a product is shown below. (2points) Demand Probability 0 0.05 1 0.10 2 0.15 3 0.35 4 0.20 5 0.10 6 0.05 a. What is the expected number of units demanded per day in other words find the mean of this distribution? b. Determine the variance and the standard deviation of this distribution. ANS: a) b) 4 Stat 200, Quiz #3 4. Which of the following are characteristics of a binomial experiment? List all that applies. a. at least 2 outcomes are possible b. the probability changes from trial to trial c. the experiment has a sequence on n identical trials d. exactly two outcomes are possible on each trial e. the trials are dependent f. the probabilities of the outcomes do not change from one trial to another g. the trials are independent 5. A fair coin is tossed 10 times. Find the probability of getting exactly five heads. Use the binomial tables. 6. A fair coin is tossed 10 times. Find the probability of getting at least five heads. Use the binomial tables. 7. If 60% of all women are employed outside their home, find the probability that in a sample of 20 women a) Exactly 15 are employed. b) At least 10 are employed c) At most 5 are not employed outside the home ANS: a) , b) , c) 8. If 80% of the applicants are able to pass a driver's proficiency road test, find the mean, variance and standard deviation of the number of people who pass the test in a sample of 300 applicants 5 Stat 200, Quiz #3 9. A study conducted to determine the number of telephones each household has. The data are shown here. Construct a probability distribution and draw a graph for the data. Number of telephones 0 Frequency 2 1 2 3 30 48 13 6 4 7