MATH 302 QUIZ 2 – QUESTION AND ANSWERS – SET 2 ( LATEST UPDATE )

MATH 302 QUIZ 2 – QUESTION AND ANSWERS – SET 2 Question 1 of 20 1.0/ 1.0 Points The probability of an event and the probability of its complement always sum to: A. 0 B. any value between 0 and 1 C. any positive value D. 1.0 Answer Key: D Question 2 of 20 1.0/ 1.0 Points A jar contains four white marbles, five red marbles, and six black marbles. If a marble is selected at random, find the probability that it is white or black . A. 2/15 B. 2/3 C. 1/5 D. 2/5 Answer Key: B Question 3 of 20 1.0/ 1.0 Points If two events are independent, what is the probability that they both occur? A. 0.0 B. 0.5 C. 1.00 D. Cannot be determined from the information given Answer Key: D Question 4 of 20 1.0/ 1.0 Points If two events are mutually exclusive, what is the probability that one or the other occurs? A. Cannot be determined from the information given. B. 0.25 C. 0.50 D. 1.00 Answer Key: A Question 5 of 20 1.0/ 1.0 Points What type of probability uses sample spaces to determine the numerical probability that an event will occur? A. conditional probability B. subjective probability C. classical probability D. empirical probability Answer Key: C Part 2 of 6 - 5.0/ 5.0 Points Question 6 of 20 1.0/ 1.0 Points Find the variance of the following probability distribution. X P(X) 1 0.30 2 0.15 3 0.05 4 0.25 5 0.25 A. 1.73 B. 1.61 C. 2.60 D. 1.27 Answer Key: C Question 7 of 20 1.0/ 1.0 Points If a student randomly guesses at 20 multiple-choice questions, find the probability that the student gets exactly four correct. Each question has four possible choices. A. 0.19 B. 0.17 C. 0.08 D. 0.23 Answer Key: A Question 8 of 20 1.0/ 1.0 Points The following data were obtained from a survey of college students. The variable X represents the number of non-assigned books read during the past six months. x 0 1 2 3 4 5 P (X=x) 0.20 0.25 0.20 0.15 0.10 0.10 What is the expected value of X? A. 6.25 B. 3.65 C. 1.20 D. 2.0 Answer Key: D Question 9 of 20 1.0/ 1.0 Points A researcher surveyed college students to study their opinion about the proposed change in smoking rules. The researcher asked a group of 30 students: 12 of them supported the change, 13 of them did not, and 5 had no opinion. This is not a binomial model because... A. the students who strongly supported the change and those who only mildly supported the change are counted the same. B. there are 3 possible outcomes, not 2. C less than half of the students supported the change. D. 30 students are not enough for a good sample Answer Key: B Question 10 of 20 1.0/ 1.0 Points The following data were obtained from a survey of college students. The variable X represents the number of non-assigned books read during the past six months. x 0 1 2 3 4 5 P (X=x) 0.20 0.25 0.20 0.15 0.10 0.10 Find P( X f$leq f$ 3) A. 0.15 B. 0.80 C. 0.20 D. 0.85 Answer Key: B Part 3 of 6 - 4.0/ 4.0 Points Question 11 of 20 1.0/ 1.0 Points Click to see additional instructions In February 2002 the Argentine peso lost 70% of its value compared to the United States dollar. This devaluation drastically raised the price of imported products. According to a survey conducted by AC Nielsen in April 2002, 68% of the consumers in Argentina were buying fewer products than before the devaluation, 24% were buying the same number of products, and 8% were buying more products. Furthermore, in a trend toward purchasing less-expensive brands, 88% indicated that they had changed the brands they purchased. Suppose the following complete set of results were reported. Use the following data to answer this question. Number of Products Purchased Brands Purchased Fewer Same More Total Same 10 14 24 48 Changed 262 82 8 352 Total 272 96 32 400 Given that a consumer changed brands, what then is the probability that the consumer purchased fewer products than before? Place your answer, rounded to 4 decimal places, in the blank. 0.74 Answer Key: 0.7400|0.7500 Question 12 of 20 1.0/ 1.0 Points Click to see additional instructions A DVD rental business determines that customers will rent X number of DVDs according to the following distribution: Number of DVDs rented X 1 2 3 4 5 Probability P(X) 0.15 0.25 0.3 0.25 0.05 What is the mean number of DVDs that customers rent? Round your answer to one decimal place as necessary. For example, 4.5 would be a legitimate entry. Answer: 2.8 Answer Key: 2.8 Question 13 of 20 1.0/ 1.0 Points Click to see additional instructions The annual returns, in percentages, on stocks A and B for three possible states of the economy are given in the table below. Economy State Probability StockA StockB Good 0.5 40 20 Average 0.3 20 40 Bad 0.2 10 8 If one invested in StockA, what would be the standard deviation of the percentage return? Place your answer, in percent rounded to 1 decimal place, in the blank. For example, a standard deviation of 10.39 percent would be reported as 10.4. Do not use a percent sign. 13.0 Answer Key: 12.0|13.0 Question 14 of 20 1.0/ 1.0 Points Click to see additional instructions In February 2002 the Argentine peso lost 70% of its value compared to the United States dollar. This devaluation drastically raised the price of imported products. According to a survey conducted by AC Nielsen in April 2002, 68% of the consumers in Argentina were buying fewer products than before the devaluation, 24% were buying the same number of products, and 8% were buying more products. Furthermore, in a trend toward purchasing less-expensive brands, 88% indicated that they had changed the brands they purchased. Suppose the following complete set of results were reported. Use the following data to answer this question. Number of Products Purchased Brands Purchased Fewer Same More Total Same 10 14 24 48 Changed 262 82 8 352 Total 272 96 32 400 What is the probability that a consumer selected at random purchased the same number or more products than before? Place your answer, rounded to 4 decimal places, in the blank. .3200 Answer Key: 0.3200 Part 4 of 6 - 4.0/ 4.0 Points Question 15 of 20 1.0/ 1.0 Points Click to see additional instructions If a coin is tossed seven times, how many different outcomes are possible? Place your answer in the blank. Do not use any decimal places or commas. For example, 345 would be a legitimate entry. 128 Answer Key: 128 Question 16 of 20 1.0/ 1.0 Points Click to see additional instructions A particular brand of women's jeans is available in seven different sizes, three different colors, and three different styles. How many different jeans does the store manager need to order to have one pair of each type of jean? Place your answer in the blank. Do not use any decimal places or commas. For example, 45 would be a legitimate entry. 63 Answer Key: 63 Question 17 of 20 1.0/ 1.0 Points Click to see additional instructions An ice cream vendor sells three flavors: chocolate, strawberry, and vanilla. Forty five percent of the sales are chocolate, while 30% are strawberry, with the rest vanilla flavored. Sales are by the cone or the cup. The percentages of cones sales for chocolate, strawberry, and vanilla, are 75%, 60%, and 40%, respectively. For a randomly selected sale, define the following events: f$A_{1}f$ = chocolate chosen f$A_{2}f$ = strawberry chosen f$A_{3}f$ = vanilla chosen f$Bf$ = ice cream on a cone f$ar{B}=f$ ice cream in a cup Find the probability that the ice cream was sold in a cup and was vanilla flavor. Place your answer, rounded to 2 decimal places, in the blank. For exampe, 0.34 would be a legitimate entry. .15 Answer Key: 0.15 Question 18 of 20 1.0/ 1.0 Points Click to see additional instructions A certain system has two components. There are 10 different models of the first component and 10 different of the second. Any first component can be paired with any second component. A salesman must select 2 of the first component and 3 of the second to take on a sales call. How many different systems can the salesman select? Place your answer in the blank. Do NOT use commas. For example, 2350 would be a legitimate response. 5400 Answer Key: 5400 Part 5 of 6 - 0.0/ 1.0 Points Question 19 of 20 0.0/ 1.0 Points Jim and Mike go to a coffee shop during their lunch break and toss a coin to see who will pay. The probability that Mike will pay three days in a row is 0.125. True False Answer Key: True Part 6 of 6 - 1.0/ 1.0 Points Question 20 of 20 1.0/ 1.0 Points True or False: The probability of a success must remain the same for each trial in a binomial experiment. True False Answer Key: True