Exam 1 Flashcards
All of the following are measures of central tendency except the ____________.
Mode
Median
Range
Mean
Range
If the mean is greater than the median, then the distribution is ___________.
Skewed right
Skewed left
Bimodal
Symmetrical
Skewed Right
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.
Range
If a population distribution is skewed to the right, then, given a random sample from that population, one would expect that the ____________.
Median would be less than the mean
A quantity that measures the variation of a population or a sample relative to its mean is called the ____________.
Coefficient of variation
As the coefficient of variation _______________ risk ______________.
Increases, Increases
Which of the following is influenced the least by the occurrence of extreme values in a sample?
Median
The average of the squared deviations of the individual population measurement from the population mean is the ___________.
Variance
A normal population has 99.73 percent of the population measurements within __________ standard deviations of the mean.
Three
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.
Covariance
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 ____________.
Symmetrical
Determine whether the two events are mutually exclusive.
Consumer with an unlisted phone number and a consumer who does not drive
Not mutually exclusive
The simultaneous occurrence of events A and B is represented by the notation _______________.
A “junction” B
The set of all possible experimental outcomes is called a(n) ____________.
Sample space
If events A and B are independent, then P(A|B) is equal to _____________.
P(A)
A(n) _______________ probability is a probability assessment that is based on experience, intuitive judgment, or expertise.
Subjective
Determine whether the two events are mutually exclusive.
Unmarried person and a person with an employed spouse
Mutually exclusive
If events A and B are mutually exclusive, calculate P(A|B).
0
Mutually exclusive events have intersection = 0. Therefore, the conditional probability is also 0.
Determine whether the two events are mutually exclusive.
Voter who favors gun control and an unregistered voter
Mutually exclusive
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.
Union
If two events are independent, we can _____________ their probabilities to determine the intersection probability.
Multiply
Events that have no sample space outcomes in common, and therefore cannot occur simultaneously, are ____________.
Mutually exclusive
A(n) ____________ is the probability that one event will occur given that we know that another event already has occurred.
Conditional probability
A card is drawn from a standard deck. What is the probability the card is an ace, given that it is a club?
1/13
Two mutually exclusive events having positive probabilities are ______________ dependent.
always
If P(A|B) = .2 and P(B) = .8, determine the intersection of events A and B.
.16
Temperature (in degrees Fahrenheit) is an example of a(n) ________ variable.
Interval
An identification of police officers by rank would represent a(n) ____________ level of measurement
Ordinal
A(n) ___________________ variable is a qualitative variable such that there is no meaningful ordering or ranking of the categories.
Nominal
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
Whether a Person Has a Traffic Violation
_____ refers to describing the important aspects of a set of measurements.
Descriptive statistics
The weight of a chemical compound used in an experiment that is obtained using a well-adjusted scale represents a(n) _____________ level of measurement.
Ratio
College entrance exam scores, such as SAT scores, are an example of a(n) ________________ variable.
Interval
Jersey numbers of soccer players are an example of a(n) ___________ variable.
nominal
Examining all population measurements is called a ____.
census
A _____ is a subset of the units in a population.
sample
______________ is the science of using a sample to make generalizations about the important aspects of a population.
Statistical Inference
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.
True
A discrete random variable may assume a countable number of outcome values.
True
The standard deviation of a discrete random variable measures the spread of the population of all possible values of x.
true
The expected value of the discrete random variable x is the population mean.
true
For a discrete probability distribution, the value of p(x) for each value of x falls between −1 and 1.
False
Response Feedback:
Probability values can only fall between 0 and 1.
For a random variable X, the mean value of the squared deviations of its values from their expected value is called its ____________.
Variance
The time (in seconds) it takes for an athlete to run 50 meters is an example of a continuous random variable
True
A probability distribution of a discrete random variable is expressed as a table, graph, or ___________.
Formula
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.
The number of minutes required to run 1 mile.
