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Statistics > Exam 1 > Flashcards

Exam 1 Flashcards

1
Q

All of the following are measures of central tendency except the ____________.

Mode
Median
Range
Mean

A

Range

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2
Q

If the mean is greater than the median, then the distribution is ___________.

Skewed right
Skewed left
Bimodal
Symmetrical

A

Skewed Right

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3
Q

As a measure of variation, the sample ___________ is easy to understand and compute. It is based on the two extreme values and is therefore a highly unstable measure.

A

Range

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4
Q

If a population distribution is skewed to the right, then, given a random sample from that population, one would expect that the ____________.

A

Median would be less than the mean

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5
Q

A quantity that measures the variation of a population or a sample relative to its mean is called the ____________.

A

Coefficient of variation

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6
Q

As the coefficient of variation _______________ risk ______________.

A

Increases, Increases

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7
Q

Which of the following is influenced the least by the occurrence of extreme values in a sample?

A

Median

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8
Q

The average of the squared deviations of the individual population measurement from the population mean is the ___________.

A

Variance

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9
Q

A normal population has 99.73 percent of the population measurements within __________ standard deviations of the mean.

A

Three

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10
Q

A measure of the strength of the linear relationship between x and y that is dependent on the units in which x and y are measured.

A

Covariance

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11
Q

If the mean, median, and mode for a given population all equal 25, then we know that the shape of the distribution of the population is ____________.

A

Symmetrical

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12
Q

Determine whether the two events are mutually exclusive.

Consumer with an unlisted phone number and a consumer who does not drive

A

Not mutually exclusive

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13
Q

The simultaneous occurrence of events A and B is represented by the notation _______________.

A

A “junction” B

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14
Q

The set of all possible experimental outcomes is called a(n) ____________.

A

Sample space

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15
Q

If events A and B are independent, then P(A|B) is equal to _____________.

A

P(A)

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16
Q

A(n) _______________ probability is a probability assessment that is based on experience, intuitive judgment, or expertise.

A

Subjective

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17
Q

Determine whether the two events are mutually exclusive.

Unmarried person and a person with an employed spouse

A

Mutually exclusive

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18
Q

If events A and B are mutually exclusive, calculate P(A|B).

A

0

Mutually exclusive events have intersection = 0. Therefore, the conditional probability is also 0.

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19
Q

Determine whether the two events are mutually exclusive.

Voter who favors gun control and an unregistered voter

A

Mutually exclusive

20
Q

The ___________ of two events X and Y is another event that consists of the sample space outcomes belonging to either event X or event Y or both events X and Y.

A

Union

21
Q

If two events are independent, we can _____________ their probabilities to determine the intersection probability.

A

Multiply

22
Q

Events that have no sample space outcomes in common, and therefore cannot occur simultaneously, are ____________.

A

Mutually exclusive

23
Q

A(n) ____________ is the probability that one event will occur given that we know that another event already has occurred.

A

Conditional probability

24
Q

A card is drawn from a standard deck. What is the probability the card is an ace, given that it is a club?

A

1/13

25
Q

Two mutually exclusive events having positive probabilities are ______________ dependent.

A

always

26
Q

If P(A|B) = .2 and P(B) = .8, determine the intersection of events A and B.

A

.16

27
Q

Temperature (in degrees Fahrenheit) is an example of a(n) ________ variable.

A

Interval

28
Q

An identification of police officers by rank would represent a(n) ____________ level of measurement

A

Ordinal

29
Q

A(n) ___________________ variable is a qualitative variable such that there is no meaningful ordering or ranking of the categories.

A

Nominal

30
Q

Which of the following is a qualitative variable?

Air Temperature

Bank Account Balance

Daily Sales in a Store

Whether a Person Has a Traffic Violation

Value of Company Stock

A

Whether a Person Has a Traffic Violation

31
Q

_____ refers to describing the important aspects of a set of measurements.

A

Descriptive statistics

32
Q

The weight of a chemical compound used in an experiment that is obtained using a well-adjusted scale represents a(n) _____________ level of measurement.

A

Ratio

33
Q

College entrance exam scores, such as SAT scores, are an example of a(n) ________________ variable.

A

Interval

34
Q

Jersey numbers of soccer players are an example of a(n) ___________ variable.

A

nominal

35
Q

Examining all population measurements is called a ____.

A

census

36
Q

A _____ is a subset of the units in a population.

A

sample

37
Q

______________ is the science of using a sample to make generalizations about the important aspects of a population.

A

Statistical Inference

38
Q

The variable “home ownership” can take on one of two values, 1 if the person living in a home owns the home and zero if the person living in a home does not own the home. This is an example of a discrete random variable.

A

True

39
Q

A discrete random variable may assume a countable number of outcome values.

A

True

40
Q

The standard deviation of a discrete random variable measures the spread of the population of all possible values of x.

A

true

41
Q

The expected value of the discrete random variable x is the population mean.

A

true

42
Q

For a discrete probability distribution, the value of p(x) for each value of x falls between −1 and 1.

A

False

Response Feedback:
Probability values can only fall between 0 and 1.

43
Q

For a random variable X, the mean value of the squared deviations of its values from their expected value is called its ____________.

A

Variance

44
Q

The time (in seconds) it takes for an athlete to run 50 meters is an example of a continuous random variable

A

True

45
Q

A probability distribution of a discrete random variable is expressed as a table, graph, or ___________.

A

Formula

46
Q

Which of the following is not a discrete random variable?

The number of minutes required to run 1 mile.

The number of defects in a sample selected from a population of 100 products.

The number of criminals found in a five-mile radius of a neighborhood.

The number of times a light changes red in a 10-minute cycle.

A

The number of minutes required to run 1 mile.

Statistics (2 decks)

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