Math 302 quiz 2

A Math 302 quiz 2 Part 1 of 6 - 5.0/ 5.0 Points Question 1 of 20 1.0/ 1.0 Points The staff at a small company includes: 4 secretaries, 20 technicians, 4 engineers, 2 executives, and 50 factory workers. If a person is selected at random, what is the probability that he or she is a factory worker? A.1/4 B.1/8 Correct C.5/8 D.2/5 Answer Key: C Question 2 of 20 1.0/ 1.0 Points What is the probability of drawing two queens in a row from a standard deck of cards without replacement? A.0.0015 Correct B.0.0045 C.0.0059 D.0.0385 Answer Key: B Question 3 of 20 1.0/ 1.0 Points If a menu has a choice of 4 appetizers, 4 main courses, and 3 desserts, then the sample space for all possible dinners has how many outcomes? Correct A.48 B.16 C.28 D.3 Answer Key: A Question 4 of 20 1.0/ 1.0 Points A gumball machine contains 300 grape flavored balls, 400 cherry flavored balls, and 500 lemon flavored balls. What is the probability of getting 1 grape ball, 1 cherry ball, and 1 lemon ball if each ball was removed and then replaced before choosing the next from the machine? A.0.0264 B.0.0531 Correct C.0.0347 D.0.0482 Answer Key: C Question 5 of 20 1.0/ 1.0 Points If a die is rolled one time, find the probability of getting a number greater than 2. A.2 B.-1 C.5/6 Correct D.4/6 Answer Key: D Part 2 of 6 - 5.0/ 5.0 Points Question 6 of 20 1.0/ 1.0 Points Suppose that 50 identical batteries are being tested. After 8 hours of continuous use, assume that a given battery is still operating with a probability of 0.70 and has failed with a probability of 0.30. What is the probability that greater than 40 batteries will last at least 8 hours? A.0.0789 Correct B.0.0402 C.0.9598 D.0.4538 Answer Key: B Question 7 of 20 1.0/ 1.0 Points The binomial distribution can occur in which of the following situations? I. whenever we are interested in the number of events that occur over a given interval of time II. whenever we sample from a population with only two types of members III. whenever we perform a sequence of identical experiments, each of which has only two possible outcomes A.I only B.I and II Correct C.II and III D.All of the above Answer Key: C Question 8 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. Correct A.0.19 B.0.17 C.0.08 D.0.23 Answer Key: A Question 9 of 20 1.0/ 1.0 Points Suppose that 50 identical batteries are being tested. After 8 hours of continuous use, assume that a given battery is still operating with a probability of 0.70 and has failed with a probability of 0.30. What is the probability that fewer than 40 batteries will last at least 8 hours? Correct A.0.9211 B.0.7986 C.0.9598 D.0.0789 Answer Key: A 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 What is the variance of X? A.3.42 Correct B.2.50 C.4.32 D.2.34 Answer Key: B Part 3 of 6 - 3.0/ 4.0 Points Question 11 of 20 1.0/ 1.0 Points Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. Find the expected value of the following probability distribution. X 1 2 3 4 5 P(X) 0.05 0.20 0.35 0.25 0.15 Round your answer to two decimal place as necessary. For example, 4.56 would be a legitimate entry. Expected value = Correct3.25 Answer Key: 3.25 Question 12 of 20 0.0/ 1.0 Points Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. 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 6 P (X=x) 0.55 0.15 0.10 0.10 0.04 0.03 0.03 Find P(1 < X < 5). Place your answer, rounded to two decimal places in the blank. For example, 0.56 would be a legitimate entry. Correct0.45 Answer Key: 0.24 Question 13 of 20 1.0/ 1.0 Points Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. 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 6 P (X=x) 0.55 0.15 0.10 0.10 0.04 0.03 0.03 What is the variance of X? Place your answer, rounded to two decimal places in the blank. For example, 4.56 would be a legitimate entry. Correct2.62 Answer Key: 2.62 Question 14 of 20 1.0/ 1.0 Points Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. Find the mean of the distribution shown below. X 0 1 2 P(X) 0.24 0.31 0.45 Round your answer to two decimal place as necessary. For example, 4.56 would be a legitimate entry. Mean = Correct1.21 Answer Key: 1.21 Feedback: Expected value = (0)(0.24) + (1)(0.31) + (2)(0.45) = 1.21 Part 4 of 6 - 3.0/ 4.0 Points Question 15 of 20 1.0/ 1.0 Points Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. Mothers Against Drunk Driving (MADD) is a very visible group whose main focus is to educate the public about the harm caused by drunk drivers. A study was recently done that emphasized the problem we all face with drinking and driving. Five hundred accidents that occurred on a Saturday night were analyzed. Two items noted were the number of vehicles involved and whether alcohol played a role in the accident. The numbers are shown below: Number of Vehicles Involved Did alcohol play a role? 1 2 3 Yes 60 110 30 200 No 40 215 45 300 100 325 75 What proportion of accidents involved more than one vehicle? Place your answer, rounded to 2 decimal places, in the blank. For example, 0.23 is a legitimate entry. Correct.8 Answer Key: 0.80 Question 16 of 20 1.0/ 1.0 Points Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. A probability experiment has two steps. There are two possible results for the first step, call them "A" and "B". If the result for the first step was "A", then there would be 4 possible results for the second step. If the result for the first step was "B", then there would be 16 possible results for the second step. How many possible outcomes are there for this experiment? Place your answer in the blank. Do not use any decimal point or comma. For example, 45 would be a legitimate entry. Correct20 Answer Key: 20 Question 17 of 20 0.0/ 1.0 Points Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. 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. Correct14 Answer Key: 128 Question 18 of 20 1.0/ 1.0 Points Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. A reading list for a course contains 20 articles. How many ways are there to choose three articles from this list? Place your answer in the blank. Do not use any decimal places or commas. For example, 45 would be a legitimate entry. Correct1140 Answer Key: 1140 Part 5 of 6 - 0.0/ 1.0 Points Question 19 of 20 0.0/ 1.0 Points Two events A and B are said to be independent if P(A and B) = P(A) + P(B)Incorrect True False Answer Key: False Part 6 of 6 - 1.0/ 1.0 Points Question 20 of 20 1.0/ 1.0 Points The expected number of tails in 500 tosses of an unbiased coin is 200. Correct True False Answer Key: False