BIA Ch 1-6

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Which of the following variables uses the ratio scale of measurement? a. time b. name of stock exchange c. SAT scores d. social security number

A. Time

Statistics can be referred to as numerical facts. In a broader sense, statistics is the field of study dealing with the collection, analysis, presentation and interpretation of data.

True

Four percent of the customers of a mortgage company default on their payments. A sample of five customers is selected. What is the probability that exactly two customers in the sample will default on their payments? a. .0142 b. .2592 c. .7408 d. .9588

a. .0142

The probability Pete will catch fish when he goes fishing is .8. Pete is going fishing 3 days next week. The probability that Pete will catch fish on 1 or fewer days is _____. a. .104 b. .8 c. .096 d. .008

a. .104

The assembly time for a product is uniformly distributed between 6 and 10 minutes. The probability of assembling the product between 7 and 9 minutes is _____. a. .50 b. 1 c. .20 d. 0

a. .50

If A and B are independent events with P(A) = .4 and P(B) = .25, then P(A ∪ B) = _____. a. .55 b. .10 c. .65 d. Not enough information is given to answer this question.

a. .55

If P(A) = .75, P(A ∪ B) = .86, and P(A ∩ B) = .56, then P(B) = a. .67 b. .56 c. .11 d. .25

a. .67

If P(A) = .62, P(B) = .56, and P(A ∪ B) = .70, then P(B | A) = _____. a. .7742 b. .9032 c. .4800 d. Not enough information is given to answer this question.

a. .7742

If the data distribution is symmetric, the skewness is _____. a. 0 b. .5 c. 1 d. None of these answers are correct.

a. 0

For the standard normal probability distribution, the area to the left of the mean is _____. a. 0.5 b. 1 c. any value between 0 and 1 d. -.5

a. 0.5

Given that z is a standard normal random variable, what is the value of z if the area to the left of z is .9382? a. 1.54 b. 2.1 c. 1.8 d. 1.77

a. 1.54

What organization developed the report, "Ethical Guidelines for Statistical Practice"? a. American Statistical Association b. Ethics Committee for Statistical Practices c. International Statistical Organization d. Federal Bureau for Ethical Practices in Statistics

a. American Statistical Association

Which of the following is NOT a characteristic of an experiment where the binomial probability distribution is applicable? a. The trials are dependent. b. The probabilities of the outcomes do not change from one trial to another. c. Exactly two outcomes are possible on each trial. d. The experiment has a sequence of n identical trials.

a. The trials are dependent.

Which of the following statements about a discrete random variable and its probability distribution is true? a. Values of f(x) must be greater than or equal to zero. b. Values of the random variable can never be negative. c. Negative values of f(x) are allowed if Σf(x) = 1. d. The values of f(x) increase to a maximum point and then decrease.

a. Values of f(x) must be greater than or equal to zero.

In an experiment, events A and B are mutually exclusive. If P(A) = .6, then the probability of B _____. a. cannot be larger than .4 b. can be any value between 0 and 1 c. can be any value greater than .6 d. Cannot be determined with the information given.

a. cannot be larger than .4

When the assumption of equally likely outcomes is used to assign probability values, the method used to assign probabilities is referred to as the _____. a. classical method b. subjective method c. relative frequency method d. probability method

a. classical method

Which of the following is NOT a measure of variability of a single variable? a. covariance b. range c. coefficient of variation d. standard deviation

a. covariance

The owner of a factory regularly requests a graphical summary of all employees' salaries. The graphical summary of salaries is an example of _____. a. descriptive statistics b. an experiment c. statistical inference d. a sample

a. descriptive statistics

The summaries of data, which may be tabular, graphical, or numerical, are referred to as _____. a. descriptive statistics b. inferential statistics c. statistical inference d. report generation

a. descriptive statistics

The measure of location often used in analyzing growth rates in financial data is the _____. a. geometric mean b. arithmetic mean c. weighted mean d. hyperbolic mean

a. geometric mean

The expected value of a discrete random variable _____. a. is the average value for the random variable over many repeats of the experiment b. will always be one of the values x can take on, although it may not be the highest probability value for the random variable c. is the most likely or highest probability value for the random variable d. All of these answers are correct.

a. is the average value for the random variable over many repeats of the experiment

Statistical inference _____. a. is the process of drawing inferences about the population based on the information taken from the sample b. is the same as descriptive statistics c. refers to the process of drawing inferences about the sample based on the characteristics of the population d. is the same as a census

a. is the process of drawing inferences about the population based on the information taken from the sample

The coefficient of variation indicates how large the standard deviation is relative to the _____. a. mean b. variance c. median d. range

a. mean

The 50th percentile is the _____. a. median b. mean c. mode d. third quartile

a. median

For data skewed to the left, the skewness is _____. a. negative b. positive c. between 0 and .5 d. less than 1

a. negative

The mean, median, and mode have the same value for which of the following probability distributions? a. normal b. Poisson c. uniform d. exponential

a. normal

A(n) _____ is an unusually small or unusually large data value. a. outlier b. sample statistic c. median d. z-score

a. outlier

A numerical description of the outcome of an experiment is called a _____. a. random variable b. probability function c. variance d. descriptive statistic

a. random variable

Six hundred residents of a city are polled to obtain information on voting intentions in an upcoming city election. The 600 residents in this study is an example of a(n) _____. a. sample b. census c. population d. observation

a. sample

For a standard normal distribution, a negative value of z indicates _____. a. the z is to the left of the mean b. the z is to the right of the mean c. the area corresponding to the z is negative d. a mistake has been made in computations, because z is always positive

a. the z is to the left of the mean

The 75th percentile is also the _____. a. third quartile b. second quartile c. first quartile d. fourth quartile

a. third quartile

A graphical device used for enumerating sample points in a multiple-step experiment is a _____. a. tree diagram b. histogram c. bar chart d. None of these answers are correct.

a. tree diagram

Which of the following is NOT a measure of location? a. variance b. mean c. median d. mode

a. variance

Which of the following values of r indicates the strongest correlation? a. −.9 b. .82 c. 0 d. .361

a. −.9

If A and B are mutually exclusive events with P(A) = .3 and P(B) = 0.5, then P(A ∩ B) = a. .30 b. 0 c. .20 d. .15

b. 0

If X and Y are mutually exclusive events with P(X) = .295, P(Y) = .32, then P(X ∪ Y) = _____. a. 1 b. 0 c. .094 d. .615

b. 0

Given that z is a standard normal random variable, what is the value of z if the area to the right of z is .1401? a. .1401 b. 1.08 c. -1.08 d. 2.16

b. 1.08

Assume z is a standard normal random variable. What is the value of z if the area between -z and z is .754? a. .123 b. 1.16 c. 2.16 d. .377

b. 1.16

Suppose we flip a fair coin five times and each time it lands heads up. The probability of landing heads up on the next flip is _____. a. 1 b. 1/2 c. 0 d. None of these answers are correct.

b. 1/2

Of five letters (A, B, C, D, and E), two letters are to be selected at random. How many possible selections are there? a. 7 b. 10 c. 20 d. 5!

b. 10

Suppose annual salaries for sales associates from Hayley's Heirlooms have a bell-shaped distribution with a mean of $32,500 and a standard deviation of $2,500.The z-score for a sales associate from this store who earns $37,500 is _____. a. .92 b. 2 c. 37.5 d. −2

b. 2

Twenty percent of the students in a class of 100 are planning to go to graduate school. The standard deviation of this binomial distribution is _____. a. 20 b. 4 c. 2 d. 16

b. 4

The "Top Three" at a racetrack consists of picking the correct order of the first three horses in a race. If there are 10 horses in a particular race, how many "Top Three" outcomes are there? a. 302,400 b. 720 c. 10 d. 1,814,400

b. 720

Each customer entering a department store will either buy or not buy some merchandise. An experiment consists of following three customers and determining whether or not they purchase any merchandise. The number of sample points in this experiment is _____. a. 6 b. 8 c. 2 d. 4

b. 8

Which of the following statements is always true? a. P(A) + P(B) = 1 b. P(A) = 1 − P(Ac) c. −1 ≤ P(Ei) ≤ 1 d. both P(A) = 1 − P(Ac) and P(A) + P(B) = 1

b. P(A) = 1 − P(Ac)

Which of the following is NOT a characteristic of the normal probability distribution? a. The total area under the curve is always equal to 1. b. The graph of the curve is the shape of a rectangle. c. The mean is equal to the median, which is also equal to the mode. d. The random variable assumes a value within plus or minus three standard deviations of its mean 99.72% of the time.

b. The graph of the curve is the shape of a rectangle.

Which of the following is a characteristic of a binomial experiment? a. The probability of success changes from trial to trial. b. The trials are independent. c. At least two outcomes are possible. d. All of these answers are correct.

b. The trials are independent

A standard normal distribution is a normal distribution with _____. a. a mean of 1 and a standard deviation of 0 b. a mean of 0 and a standard deviation of 1 c. any mean and any standard deviation d. any mean and a standard deviation of 1

b. a mean of 0 and a standard deviation of 1

Data collected at the same, or approximately the same, point in time are _____ data. a. time series b. cross-sectional c. one-dimensional d. static

b. cross-sectional

A set of visual displays organizing and presenting information used to monitor the performance of a company or organization in a manner that is easy to read, understand, and interpret is called a _____. a. crosstabulation b. data dashboard c. stem-and-leaf display d. stacked bar chart

b. data dashboard

The standard deviation of a standard normal distribution _____. a. can be any positive value b. is always equal to 1 c. is always equal to 0 d. can be any value

b. is always equal to 1

For a uniform probability density function, the height of the function _____. a. decreases as x increases b. is the same for each value of x c. is different for various values of x d. cannot be larger than1

b. is the same for each value of x

You roll a fair six-sided die with the hopes of rolling a 5 or a 6. These two events are ___________ because they have no sample points in common. a. posterior events b. mutually exclusive events c. independent events d. complements

b. mutually exclusive events

In a binomial experiment, the _____. a. probability of success does change from trial to trial b. probability of success does not change from trial to trial c. probability of success could change from trial to trial, depending on the situation under consideration d. All of these answers are correct.

b. probability of success does not change from trial to trial

When the results of experimentation or historical data are used to assign probability values, the method used to assign probabilities is referred to as the _____. a. posterior method b. relative frequency method c. classical method d. subjective method

b. relative frequency method

A weighted average of the value of a random variable, where the probability function provides weights, is known as _____. a. a random variable b. the expected value c. a probability function d. None of these answers are correct.

b. the expected value

The highest point of a normal curve occurs at _____. a. one standard deviation to the right of the mean b. the mean c. two standard deviations to the right of the mean d. approximately three standard deviations to the right of the mean

b. the mean

The student body of a large university consists of 60% female students. A random sample of 8 students is selected. What is the random variable in this experiment? a. the student body size b. the number of female students out of 8 c. the random sample of 8 students d. the 60% of female students

b. the number of female students out of 8

The sample space refers to _____. a. any particular experimental outcome b. the set of all possible experimental outcomes c. the sample size minus 1 d. both any particular experimental outcome and the set of all possible experimental outcome

b. the set of all possible experimental outcomes

If A and B are independent events with P(A) = .05 and P(B) = .65, then P(A | B) = _____. a. .65 b. .8 c. .05 d. .0325

c. .05

An experiment consists of four outcomes with P(E1) = .2, P(E2) = .3, and P(E3) = .4. The probability of outcome E4 is _____. a. .024 b. .900 c. .100 d. .500

c. .100

The student body of a large university consists of 60% female students. A random sample of 8 students is selected. What is the probability that among the students in the sample at least 7 are female? a. .0168 b. .8936 c. .1064 d. .0896

c. .1064

If A and B are independent events with P(A) = .2 and P(B) = .6, then P(A ∪ B) = _____. a. .60 b. .12 c. .68 d. .62

c. .68

The probability Pete will catch fish when he goes fishing is .8. Pete is going fishing 3 days next week. The expected number of days Pete will catch fish is _____. a. .6 b. 3 c. 2.4 d. .8

c. 2.4

Which of the following is not a measure of dispersion? a. range b. standard deviation c. 50th percentile d. interquartile range

c. 50th percentile

Which of the following is NOT a characteristic of the normal probability distribution? a. The distribution is symmetrical. b. The mean of the distribution can be negative, zero, or positive. c. The standard deviation must be 1. d. The mean, median, and mode are equal.

c. The standard deviation must be 1.

A marketing manager instructs his team to make 80 telephone calls to attempt to sell an insurance policy. The random variable in this experiment is the number of sales made. This random variable is a _____. a. continuous random variable b. complex random variable c. discrete random variable d. None of these answers are correct.

c. discrete random variable

A random variable that can assume only a finite number of values is referred to as a(n) _____. a. discrete probability function b. infinite sequence c. discrete random variable d. finite sequence

c. discrete random variable

A measure of the average value of a random variable is called a(n) _____. a. standard deviation b. variance c. expected value d. None of these answers are correct

c. expected value

When the data are positively skewed, the mean will usually be _____. a. greater than the mode b. less than the mode c. greater than the median d. less than the median

c. greater than the median

In a five-number summary, which of the following is NOT used for data summarization? a. largest value b. median c. mean d. smallest value

c. mean

In a standard normal distribution, the range of values of z is from _____. a. -1 to 1 b. -3.09 to 3.09 c. minus infinity to infinity d. 0 to 1

c. minus infinity to infinity

The measure of variability easiest to compute, but seldom used as the only measure, is the _____. a. interquartile range b. standard deviation c. range d. variance

c. range

A numerical measure computed from a sample, such as sample mean, is known as a _____. a. population parameter b. population statistic c. sample statistic d. sample parameter

c. sample statistic

The variance is a weighted average of the _____. a. square root of the deviations from the median b. square root of the deviations from the mean c. squared deviations from the mean d. squared deviations from the median

c. squared deviations from the mean

In a sample of 3,200 registered voters, 1,440, or 45%, approve of the way the president is doing his job. Refer to Exhibit 1-2. A political pollster states, "Forty five percent of all voters approve of the president." This statement is an example of _____. a. descriptive statistics b. a population c. statistical inference d. a sample

c. statistical inference

The process of analyzing sample data to draw conclusions about the characteristics of a population is called _____. a. descriptive statistics b. data summarization c. statistical inference d. data analysis

c. statistical inference

The collection of all elements of interest in a study is _____. a. descriptive statistics b. statistical inference c. the population d. the sampling

c. the population

Larger values of the standard deviation result in a normal curve that is _____. a. shifted to the right b. narrower and more peaked c. wider and flatter d. shifted to the left

c. wider and flatter

On a December day, the probability of snow is .30. The probability of a "cold" day is .50. The probability of snow and a "cold" day is .15. Are snow and "cold" weather independent events? a. only when they are also mutually exclusive b. no c. yes d. only if given that it snowed

c. yes

Which of the following is NOT a categorical variable? a. your cell phone area code b. your high school graduation year c. your age on your last birthday d. your accounting class start time

c. your age on your last birthday

Which of the following symbols represents the standard deviation of a population? a. μ b. x̄ c. σ d. σ 2

c. σ

The student body of a large university consists of 60% female students. A random sample of 8 students is selected. What is the probability that among the students in the sample exactly two are female? a. .0896 b. .2936 c. .0007 d. .0413

d. .0413

The student body of a large university consists of 60% female students. A random sample of 8 students is selected.What is the probability that among the students in the sample at least 6 are male? a. .0007 b. .0079 c. .0413 d. .0499

d. .0499

If A and B are independent events with P(A) = .4 and P(B) = .6, then P(A ∩ B) = _____. a. 1 b. .76 c. .2 d. .24

d. .24

The probability density function for a uniform distribution ranging between 2 and 6 is _____. a. any positive value b. 4 c. undefined d. .25

d. .25

The assembly time for a product is uniformly distributed between 6 and 10 minutes. The probability of assembling the product in 7 minutes or more is _____. a. 0 b. 1 c. .25 d. .75

d. .75

For any continuous random variable, the probability that the random variable takes on exactly a specific value is _____. a. .50 b. any value between 0 and 1 c. 1 d. 0

d. 0

The range of probability is _____, a. any value between minus infinity to plus infinity b. any value between -1 to 1 c. any value larger than 0 d. 0 to 1, inclusive

d. 0 to 1, inclusive

Assume your favorite football team has two games left to finish the season. The outcome of each game can be win, lose, or tie. The number of possible outcomes is _____. a. 4 b. 6 c. 2 d. 9

d. 9

A Scanner Data User Survey of 50 companies found that the average amount spent on scanner data per category of consumer goods was $387,325 (Mercer Management Consulting, Inc., April 24, 1997). The $387,325 is an example of _____. a. quantitative data b. categorical data c. a descriptive statistic d. Both quantitative data and a descriptive statistic are correct.

d. Both quantitative data and a descriptive statistic are correct.

If P(A) = .5 and P(B) = .5, then P(A ∩ B) _____. a. is 0 b. is 1 c. is .25 d. Cannot be determined from the information given

d. Cannot be determined from the information given

_____ analytics encompasses the set of analytical techniques that describe what has happened in the past. a. Data b. Prescriptive c. Predictive d. Descriptive

d. Descriptive

The Microsoft Office package used to perform statistical analysis is _____. a. SPSS b. Word c. SAS d. Excel

d. Excel

Which of the following is(are) required condition(s) for a discrete probability function? a. f(x) ≥ 1 for all values of x b. Σf(x) = 0 c. f(x) < 0 d. None of these answers are correct

d. None of these answers are correct

A method of assigning probabilities based upon judgment is referred to as the _____. a. relative frequency method b. probability method c. classical method d. None of these answers are correct.