Quant 1 Final
4) The estimation of the population average family expenditure on food based on the sample average expenditure of 1,000 families is an example of A) inferential statistics. B) descriptive statistics. C) a parameter. D) a statistic.
A) inferential statistics.
8) A summary measure that is computed to describe a characteristic of an entire population is called A) a parameter. B) a census. C) a statistic. D) the scientific method.
A) a parameter.
6) The portion of the universe that has been selected for analysis is called A) a sample. B) a frame. C) a parameter. D) a statistic.
A) a sample.
7) Whenever p = 0.5, the binomial distribution will A) always be symmetric. B) be symmetric only if n is large. C) be right-skewed. D) be left-skewed.
A) always be symmetric.
3) A probability distribution is an equation that A) associates a particular probability of occurrence with each outcome in the sample space. B) measures outcomes and assigns values of X to the simple events. C) assigns a value to the variability in the sample space. D) assigns a value to the center of the sample space.
A) associates a particular probability of occurrence with each outcome in the sample space.
12) What type of probability distribution will the consulting firm most likely employ to analyze the insurance claims in the following problem? An insurance company has called a consulting firm to determine if the company has an unusually high number of false insurance claims. It is known that the industry proportion for false claims is 3%. The consulting firm has decided to randomly and independently sample 100 of the company's insurance claims. They believe the number of these 100 that are false will yield the information the company desires. A) binomial distribution B) Poisson distribution C) hypergeometric distribution D) None of the above.
A) binomial distribution
14) What type of probability distribution will most likely be used to analyze warranty repair needs on new cars in the following problem? The service manager for a new automobile dealership reviewed dealership records of the past 20 sales of new cars to determine the number of warranty repairs he will be called on to perform in the next 90 days. Corporate reports indicate that the probability any one of their new cars needs a warranty repair in the first 90 days is 0.15. The manager assumes that calls for warranty repair are independent of one another and is interested in predicting the number of warranty repairs he will be called on to perform in the next 90 days for this batch of 20 new cars sold. A) binomial distribution B) Poisson distribution C) hypergeometric distribution D) None of the above.
A) binomial distribution
19) A company has 125 personal computers. The probability that any one of them will require repair on a given day is 0.025. To find the probability that exactly 2 of the computers will require repair on a given day, one will use what type of probability distribution? A) binomial distribution B) Poisson distribution C) hypergeometric distribution D) None of the above.
A) binomial distribution
22) A multiple-choice test has 30 questions. There are 4 choices for each question. A student who has not studied for the test decides to answer all questions randomly. What type of probability distribution can be used to figure out his chance of getting at least 20 questions right? A) binomial distribution B) Poisson distribution C) hypergeometric distribution D) None of the above.
A) binomial distribution
10) Simple probability of an event in a contingency table is also called A) marginal probability. B) joint probability. C) conditional probability. D) Bayes' theorem.
A) marginal probability.
6) If event A and event B cannot occur at the same time, then events A and B are said to be A) mutually exclusive. B) statistically independent. C) collectively exhaustive. D) None of the above.
A) mutually exclusive.
1) The process of using sample statistics to draw conclusions about true population parameters is called A) statistical inference. B) the scientific method. C) sampling. D) descriptive statistics.
A) statistical inference.
2) If two events are mutually exclusive, what is the probability that both occur at the same time? A) 0 B) 0.50 C) 1.00 D) Cannot be determined from the information given.
A) 0
13) According to the empirical rule, if the data form a "bell-shaped" normal distribution, ________ percent of the observations will be contained within 1 standard deviation around the arithmetic mean. A) 68.26 B) 75.00 C) 88.89 D) 93.75
A) 68.26
4) Which of the following statements about the median is not true? A) It is more affected by extreme values than the arithmetic mean. B) It is a measure of central tendency. C) It is equal to Q2. D) It is equal to the mode in bell-shaped "normal" distributions.
A) It is more affected by extreme values than the arithmetic mean.
11) When using the general multiplication rule, P(A and B) is equal to A) P(A|B)P(B). B) P(A)P(B). C) P(B)/P(A). D) P(A)/P(B).
A) P(A|B)P(B).
11) True or False: A population is the totality of items or things under consideration. A) True B) False
A) True
12) True or False: A sample is the portion of the universe that is selected for analysis. 12) True or False: A sample is the portion of the universe that is selected for analysis. A) True B) False
A) True
12) True or False: When A and B are mutually exclusive, P(A or B) can be found by adding P(A) and P(B). A) True B) False
A) True
13) True or False: Problems may arise when statistically unsophisticated users who do not understand the assumptions behind the statistical procedures or their limitations are misled by results obtained from computer software. A) True B) False
A) True
13) True or False: The collection of all the possible events is called a sample space. A) True B) False
A) True
14) True or False: A statistic is usually used to provide an estimate for a usually unobserved parameter. A) True B) False
A) True
14) True or False: If A and B cannot occur at the same time they are called mutually exclusive. A) True B) False
A) True
16) True or False: A professor computed the sample average exam score of 20 students and used it to estimate the average exam score of the 1,500 students taking the exam was an example of inferential statistics. A) True B) False
A) True
16) True or False: If either A or B must occur they are called collectively exhaustive. A) True B) False
A) True
17) True or False: Compiling the number of registered voters who turned out to vote for the primary in Iowa is an example of descriptive statistics. A) True B) False
A) True
17) True or False: If P(A or B) = 1.0, then A and B must be mutually exclusive. A) True B) False
A) True
17) True or False: The median of the values 3.4, 4.7, 1.9, 7.6, and 6.5 is 4.05. A) True B) False
A) True
18) True or False: If P(A or B) = 1.0, then A and B must be collectively exhaustive. A) True B) False
A) True
18) True or False: In a set of numerical data, the value for Q3 can never be smaller than the value for Q1. A) True B) False
A) True
19) True or False: If P(A and B) = 1.0, then A and B must be mutually exclusive and collectively exhaustive. A) True B) False
A) True
20) True or False: Suppose A and B are independent events where P(A) = 0.4 and P(B) = 0.5. Then P(A and B) =0.2. A) True B) False
A) True
22) True or False: Suppose A and B are mutually exclusive events where P(A) = 0.4 and P(B) = 0.5. Then P(A or B) = 0.9. A) True B) False
A) True
23) True or False: In exploratory data analysis, a boxplot can be used to illustrate the median, quartiles, and extreme values. A) True B) False
A) True
23) True or False: Suppose A and B are independent events where P(A) = 0.4 and P(B) = 0.5. Then P(A or B) = 0.7. A) True B) False
A) True
24) True or False: Another name for the mean of a probability distribution is its expected value. A) True B) False
A) True
24) True or False: Suppose A and B are events where P(A) = 0.4, P(B) = 0.5, and P(A and B) = 0.1. Then P(A or B) = 0.8. A) True B) False
A) True
24) True or False: The median of a data set with 20 items would be the average of the 10th and the 11th items in the ordered array. A) True B) False
A) True
25) True or False: Suppose A and B are events where P(A) = 0.4, P(B) = 0.5, and P(A and B) = 0.1. Then P(A|B) = 0.2. A) True B) False
A) True
25) True or False: The coefficient of variation measures variability in a data set relative to the size of the arithmetic mean. A) True B) False
A) True
26) True or False: Suppose A and B are events where P(A) = 0.4, P(B) = 0.5, and P(A and B) = 0.1. Then P(B|A) = 0.25. A) True B) False
A) True
27) True or False: The interquartile range is a measure of variation or dispersion in a set of data. A) True B) False
A) True
28) True or False: If a set of data is perfectly symmetrical, the arithmetic mean must be identical to the median. A) True B) False
A) True
29) True or False: The coefficient of variation is a measure of relative variation. A) True B) False
A) True
30) True or False: The Z scores can be used to identify outliers. A) True B) False
A) True
31) True or False: As a general rule, an observation is considered an extreme value if its Z score is greater than 3. A) True B) False
A) True
32) True or False: The Z score of an observation measures how many standard deviations is the value from the mean. A) True B) False
A) True
2) A campus program evenly enrolls undergraduate and graduate students. If a random sample of 4 students is selected from the program to be interviewed about the introduction of a new fast food outlet on the ground floor of the campus building, what is the probability that all 4 students selected are undergraduate students? A) 0.0256 B) 0.0625 C) 0.16 D) 1.00
B) 0.0625
10) If n = 10 and p = 0.70, then the standard deviation of the binomial distribution is: A) 0.07 B) 1.45 C) 7.00 D) 14.29
B) 1.45
15) True or False: A statistic is usually unobservable while a parameter is usually observable. A) True B) False
B) False
15) True or False: If either A or B must occur they are called mutually exclusive. A) True B) False
B) False
16) True or False: The median of the values 3.4, 4.7, 1.9, 7.6, and 6.5 is 1.9. A) True B) False
B) False
19) True or False: In a set of numerical data, the value for Q2 is always halfway between Q1 and Q3. A) True B) False
B) False
20) True or False: The line drawn within the box of the boxplot always represents the arithmetic mean. A) True B) False
B) False
21) True or False: Suppose A and B are mutually exclusive events where P(A) = 0.4 and P(B) = 0.5. Then P(A and B) = 0.2. A) True B) False
B) False
22) True or False: A population with 200 elements has an arithmetic mean of 10. From this information, it can be shown that the population standard deviation is 15. A) True B) False
B) False
23) True or False: The Poisson distribution can be used to model a continuous random variable. A) True B) False
B) False
26) True or False: The coefficient of variation is a measure of central tendency in the data. A) True B) False
B) False
15) What type of probability distribution will most likely be used to analyze the number of chocolate chip parts per cookie in the following problem? The quality control manager of Marilyn's Cookies is inspecting a batch of chocolate chip cookies. When the production process is in control, the average number of chocolate chip parts per cookie is 6.0. The manager is interested in analyzing the probability that any particular cookie being inspected has fewer than 5.0 chip parts. A) binomial distribution B) Poisson distribution C) hypergeometric distribution D) None of the above.
B) Poisson distribution
18) A professor receives, on average, 24.7 e-mails from students the day before the midterm exam. To compute the probability of receiving at least 10 e-mails on such a day, he will use what type of probability distribution? A) binomial distribution B) Poisson distribution C) hypergeometric distribution D) None of the above.
B) Poisson distribution
21) On the average, 1.8 customers per minute arrive at any one of the checkout counters of a grocery store. What type of probability distribution can be used to find out the probability that there will be no customer arriving at a checkout counter? A) binomial distribution B) Poisson distribution C) hypergeometric distribution D) None of the above.
B) Poisson distribution
9) In right-skewed distributions, which of the following is the correct statement? A) The distance from Q1 to Q2 is larger than the distance from Q2 to Q3. B) The distance from Q1 to Q2 is smaller than the distance from Q2 to Q3. C) The arithmetic mean is smaller than the median. D) The mode is larger than the arithmetic mean.
B) The distance from Q1 to Q2 is smaller than the distance from Q2 to Q3.
11) In left-skewed distributions, which of the following is the correct statement? A) The distance from Q1 to Q2 is smaller than the distance from Q2 to Q3. B) The distance from the smallest observation to Q1 is larger than the distance from Q3 to the largest observation. C) The distance from the smallest observation to Q2 is smaller than the distance from Q2 to the largest observation. D) The distance from Q1 to Q3 is twice the distance from Q1 to Q2.
B) The distance from the smallest observation to Q1 is larger than the distance from Q3 to the largest observation.
10) Which of the following is most likely a parameter as opposed to a statistic? A) The average score of the first five students completing an assignment. B) The proportion of females registered to vote in a county. C) The average height of people randomly selected from a database. D) The proportion of trucks stopped yesterday that were cited for bad brakes.
B) The proportion of females registered to vote in a county.
5) The universe or "totality of items or things" under consideration is called A) a sample. B) a population. C) a parameter. D) a statistic.
B) a population.
8) The collection of all possible events is called A) a simple probability. B) a sample space. C) a joint probability. D) the null set.
B) a sample space.
3) The collection and summarization of the socioeconomic and physical characteristics of the employees of a particular firm is an example of A) inferential statistics. B) descriptive statistics. C) a parameter. D) a statistic.
B) descriptive statistics.
8) Whenever p = 0.1 and n is small, the binomial distribution will be A) symmetric. B) right-skewed. C) left-skewed. D) None of the above.
B) right-skewed.
5) If the outcome of event A is not affected by event B, then events A and B are said to be A) mutually exclusive. B) statistically independent. C) collectively exhaustive. D) None of the above.
B) statistically independent.
4) The connotation "expected value" or "expected gain" from playing roulette at a casino means A) the amount you expect to "gain" on a single play. B) the amount you expect to "gain" in the long run over many plays. C) the amount you need to "break even" over many plays. D) the amount you should expect to gain if you are lucky.
B) the amount you expect to "gain" in the long run over many plays.
2) Which of the arithmetic mean, median, mode, and geometric mean are resistant to outliers? A) the arithmetic mean and median only B) the median and mode only C) the mode and geometric mean only D) the arithmetic mean and mode only
B) the median and mode only
3) In a right-skewed distribution A) the median equals the arithmetic mean. B) the median is less than the arithmetic mean. C) the median is larger than the arithmetic mean. D) None of the above.
B) the median is less than the arithmetic mean.
6) In a binomial distribution A) the random variable X is continuous. B) the probability of event of interest π is stable from trial to trial. C) the number of trials n must be at least 30. D) the results of one trial are dependent on the results of the other trials.
B) the probability of event of interest π is stable from trial to trial.
1) If two events are collectively exhaustive, what is the probability that one or the other occurs? A) 0 B) 0.50 C) 1.00 D) Cannot be determined from the information given.
C) 1.00
9) If n = 10 and p = 0.70, then the mean of the binomial distribution is: A) 0.07 B) 1.45 C) 7.00 D) 14.29
C) 7.00
7) A summary measure that is computed to describe a characteristic from only a sample of the population is called A) a parameter. B) a census. C) a statistic. D) the scientific method.
C) a statistic.
13) The covariance A) must be between -1 and +1. B) must be positive. C) can be positive or negative. D) must be less than +1.
C) can be positive or negative.
7) If either event A or event B must occur, then events A and B are said to be A) mutually exclusive. B) statistically independent. C) collectively exhaustive. D) None of the above.
C) collectively exhaustive.
16) What type of probability distribution will most likely be used to analyze the number of cars with defective radios in the following problem? From an inventory of 48 new cars being shipped to local dealerships, corporate reports indicate that 12 have defective radios installed. The sales manager of one dealership wants to predict the probability out of the 8 new cars it just received that, when each is tested, no more than 2 of the cars have defective radios. A) binomial distribution B) Poisson distribution C) hypergeometric distribution D) None of the above.
C) hypergeometric distribution
17) A stock analyst was provided with a list of 25 stocks. He was expected to pick 3 stocks from the list whose prices are expected to rise by more than 20% after 30 days. In reality, the prices of only 5 stocks would rise by more than 20% after 30 days. If he randomly selected 3 stocks from the list, he would use what type of probability distribution to compute the probability that all of the chosen stocks would appreciate more than 20% after 30 days? A) binomial distribution B) Poisson distribution C) hypergeometric distribution D) None of the above.
C) hypergeometric distribution
20) A financial analyst is presented with information on the past records of 60 start-up companies and told that in fact only 3 of them have managed to become highly successful. He selected 3 companies from this group as the candidates for success. To analyze his ability to spot the companies that will eventually become highly successful, he will use what type of probability distribution? A) binomial distribution B) Poisson distribution C) hypergeometric distribution D) None of the above.
C) hypergeometric distribution
7) When extreme values are present in a set of data, which of the following descriptive summary measures are most appropriate? A) Coefficient of Variation (CV) and range B) arithmetic mean and standard deviation C) interquartile range and median D) variance and interquartile range
C) interquartile range and median
11) If the outcomes of a random variable follow a Poisson distribution, then their A) mean equals the standard deviation. B) median equals the standard deviation. C) mean equals the variance. D) median equals the variance.
C) mean equals the variance.
6) In a perfectly symmetrical distribution A) the range equals the interquartile range. B) the interquartile range equals the arithmetic mean. C) the median equals the arithmetic mean. D) the variance equals the standard deviation.
C) the median equals the arithmetic mean.
1) Thirty-six of the staff of 80 teachers at a local intermediate school are certified in Cardio-Pulmonary Resuscitation (CPR). In 180 days of school, about how many days can we expect that the teacher on bus duty will likely be certified in CPR? A) 5 days B) 45 days C) 65 days D) 81 days
D) 81 days
12) According to the empirical rule, if the data form a "bell-shaped" normal distribution, ________ percent of the observations will be contained within 2 standard deviations around the arithmetic mean. A) 68.26 B) 88.89 C) 93.75 D) 95.44
D) 95.44
14) According to the empirical rule, if the data form a "bell-shaped" normal distribution, ________ percent of the observations will be contained within 3 standard deviations around the arithmetic mean. A) 68.26 B) 75.00 C) 95.0 D) 99.7
D) 99.7
5) In a perfectly symmetrical bell-shaped "normal" distribution A) the arithmetic mean equals the median. B) the median equals the mode. C) the arithmetic mean equals the mode. D) All of the above.
D) All of the above.
8) The smaller the spread of scores around the arithmetic mean, A) the smaller the interquartile range. B) the smaller the standard deviation. C) the smaller the coefficient of variation. D) All of the above.
D) All of the above.
3) If two events are mutually exclusive and collectively exhaustive, what is the probability that one or the other occurs? A) 0 B) 0.50 C) 1.00 D) Cannot be determined from the information given.
D) Cannot be determined from the information given.
4) If two events are independent, what is the probability that they both occur? A) 0 B) 0.50 C) 1.00 D) Cannot be determined from the information given.
D) Cannot be determined from the information given.
1) Which of the following statistics is not a measure of central tendency? A) arithmetic mean B) median C) mode D) Q3
D) Q3
10) In perfectly symmetrical distributions, which of the following is NOT a correct statement? A) The distance from Q1 to Q2 equals to the distance from Q2 to Q3. B) The distance from the smallest observation to Q1 is the same as the distance from Q3 to the largest observation. C) The distance from the smallest observation to Q2 is the same as the distance from Q2 to the largest observation. D) The distance from Q1 to Q3 is half of the distance from the smallest to the largest observation.
D) The distance from Q1 to Q3 is half of the distance from the smallest to the largest observation.
5) Which of the following about the binomial distribution is not a true statement? A) The probability of success must be constant from trial to trial. B) Each outcome is independent of the other. C) Each outcome may be classified as either "event of interest" or "not event of interest." D) The random variable of interest is continuous.
D) The random variable of interest is continuous.
2) Those methods involving the collection, presentation, and characterization of a set of data in order to properly describe the various features of that set of data are called A) statistical inference. B) the scientific method. C) sampling. D) descriptive statistics.
D) descriptive statistics.
9) Which of the following is most likely a population as opposed to a sample? A) respondents to a newspaper survey. B) the first 5 students completing an assignment. C) every third person to arrive at the bank. D) registered voters in a county.
D) registered voters in a county.
9) All the events in the sample space that are not part of the specified event are called A) simple events. B) joint events. C) the sample space. D) the complement of the event.
D) the complement of the event.
15) Which of the following is NOT a measure of central tendency? A) the arithmetic mean B) the geometric mean C) the mode D) the interquartile range
D) the interquartile range
27) You sample randomly 100 units of a recent shipment and find five units that are defective. In probability language, this result constitutes: a) An event b) An experiment c) A statistic d) A sample space
c) A statistic
28) You are applying for a job and believe there is an 85% chance that you will receive an offer from the company. In determining the 85%, you are most likely employing: a) Classical probability b) Relative frequency c) Subjective probability
c) Subjective probability
