Solutions Manual For Principles of Biostatistics 2nd Edition By
Marcello Pagano , Kimberlee Gauvreau 9781138593145 ALL
Chapters .
What are 2 broad areas into which statistical methods fall? - ANSWER: descriptive
statistics
inferential statistics
what is the purpose of descriptive statistics? - ANSWER: describe, organize, or
summarize data:
refer only to the actual data available
what is an example of descriptive statistics? - ANSWER: mean blood pressure of a
group
success rate of a surgical procedure
what is the purpose of inferential statistics? - ANSWER: making inferences that go
bayond the actual data:
usually involve inductive reasoning
what is an example of inferential statistics? - ANSWER: - mean blood pressure of all
Americans
- expected success rate of a surgical pocedure in patients who have not yet
undergone the operation
what is a population? - ANSWER: the universe about which an investigator wishes to
draw conclusions
does a population need to consist of people? - ANSWER: no
what is a sample - ANSWER: subset of the population- the part that is being observed
or studied
what is an element? - ANSWER: a single observation, denoted by X
the number of elements in a population is denoted by what? - ANSWER: N
the number of elements in a sample is denoted by what? - ANSWER: n
what does a population consist of? - ANSWER: all elements from X1 to XN
what does a sample consist of? - ANSWER: n of N elements
most samples used in biomedical research are what? - ANSWER: probability samples
,what are probability samples? - ANSWER: samples in which the researcher can
specify the probability of any one element in the population being included
probability samples permit the use of what type of statistics? - ANSWER: inferential
statistics
nonprobability samples allow what type of statistics to be used? - ANSWER:
descriptive statistics only
what are the four basic kinds of probability samples? - ANSWER: 1. simple random
samples
2. stratified random samples
3. cluster samples
4. systematic samples
what is the simplest kind of probability sample? - ANSWER: simple random sample
how is a simple random sample drawn? - ANSWER: in such a way that every element
in the population has an equal probability of being included
a random sample is defined by what? - ANSWER: the method of drawing the sample,
not by the outcome
when is a sample representative? - ANSWER: if it closely resembles the population
from which it is drawn
when does a sample or result demonstrate bias? - ANSWER: if it consistently errs in a
particular direction
are biased samples representative? - ANSWER: no, they are unrepresentative. true
randomization is proof against bias
what happens in a stratified random sample? - ANSWER: the population is first
divided into relatively internally homogenous groups, or strata, from which random
samples are then drawn.
when are cluster samples used? - ANSWER: when it is too expensive or laborious to
draw a simple random sample or stratified random sample
how is a cluster sample drawn? - ANSWER: an investigator starts by selecting a
random set of clusters and then selecting a subset of each.
how are systematic samples drawn? - ANSWER: selecting elements in a systematic
way (i.e. every 5th one)
what advantage do systematic samples provide? - ANSWER: the equivalent of a
simple random sample without actually using randomization
, what is a common sampling problem in clinical research? - ANSWER: self-selection
what is internal validity? - ANSWER: when a study is valid as far as a subset of
patients are concerned
what is external validity? - ANSWER: being valid to generalize a study to an entire
population extrapolated from a sample
the probability of an event is denoted by what? - ANSWER: p
how are probabilities expressed? - ANSWER: decimal fractions between 0-1
can the probability of an event be negative? - ANSWER: no
the probability of an event not occurring is equal to what? - ANSWER: q=1-p
what is the addition rule of probability? - ANSWER: the probability of any one of
several particular events occurring is equal to the sum of their individual
probabilities, provided the events are mutually exclusive
what is the multiplication rule of probability? - ANSWER: the probability of two or
more statistically independent events all occurring is equal to the product of their
individual probabilities
the probability that a specific combination of mutually exclusive independent evens
will occur can be determined by what? - ANSWER: binomial distribution
what is a binomial distribution? - ANSWER: one in which there are only two
possibilities, such as yes/no. the binomial distribution gives the probability of
obtaining an exact number of successes in a series of independent trials.
what is a typical medical use of the binomial distribution? - ANSWER: genetic
counseling
what are the four scales of measurement? - ANSWER: nominal
ordinal
interval
ratio
what are nominal scale data? - ANSWER: data divided into qualitative categories or
groups
is there implication of order or ratio for nominal scale data? - ANSWER: no
what are nominal data that fall into only two groups called? - ANSWER: dichotomous
data
Marcello Pagano , Kimberlee Gauvreau 9781138593145 ALL
Chapters .
What are 2 broad areas into which statistical methods fall? - ANSWER: descriptive
statistics
inferential statistics
what is the purpose of descriptive statistics? - ANSWER: describe, organize, or
summarize data:
refer only to the actual data available
what is an example of descriptive statistics? - ANSWER: mean blood pressure of a
group
success rate of a surgical procedure
what is the purpose of inferential statistics? - ANSWER: making inferences that go
bayond the actual data:
usually involve inductive reasoning
what is an example of inferential statistics? - ANSWER: - mean blood pressure of all
Americans
- expected success rate of a surgical pocedure in patients who have not yet
undergone the operation
what is a population? - ANSWER: the universe about which an investigator wishes to
draw conclusions
does a population need to consist of people? - ANSWER: no
what is a sample - ANSWER: subset of the population- the part that is being observed
or studied
what is an element? - ANSWER: a single observation, denoted by X
the number of elements in a population is denoted by what? - ANSWER: N
the number of elements in a sample is denoted by what? - ANSWER: n
what does a population consist of? - ANSWER: all elements from X1 to XN
what does a sample consist of? - ANSWER: n of N elements
most samples used in biomedical research are what? - ANSWER: probability samples
,what are probability samples? - ANSWER: samples in which the researcher can
specify the probability of any one element in the population being included
probability samples permit the use of what type of statistics? - ANSWER: inferential
statistics
nonprobability samples allow what type of statistics to be used? - ANSWER:
descriptive statistics only
what are the four basic kinds of probability samples? - ANSWER: 1. simple random
samples
2. stratified random samples
3. cluster samples
4. systematic samples
what is the simplest kind of probability sample? - ANSWER: simple random sample
how is a simple random sample drawn? - ANSWER: in such a way that every element
in the population has an equal probability of being included
a random sample is defined by what? - ANSWER: the method of drawing the sample,
not by the outcome
when is a sample representative? - ANSWER: if it closely resembles the population
from which it is drawn
when does a sample or result demonstrate bias? - ANSWER: if it consistently errs in a
particular direction
are biased samples representative? - ANSWER: no, they are unrepresentative. true
randomization is proof against bias
what happens in a stratified random sample? - ANSWER: the population is first
divided into relatively internally homogenous groups, or strata, from which random
samples are then drawn.
when are cluster samples used? - ANSWER: when it is too expensive or laborious to
draw a simple random sample or stratified random sample
how is a cluster sample drawn? - ANSWER: an investigator starts by selecting a
random set of clusters and then selecting a subset of each.
how are systematic samples drawn? - ANSWER: selecting elements in a systematic
way (i.e. every 5th one)
what advantage do systematic samples provide? - ANSWER: the equivalent of a
simple random sample without actually using randomization
, what is a common sampling problem in clinical research? - ANSWER: self-selection
what is internal validity? - ANSWER: when a study is valid as far as a subset of
patients are concerned
what is external validity? - ANSWER: being valid to generalize a study to an entire
population extrapolated from a sample
the probability of an event is denoted by what? - ANSWER: p
how are probabilities expressed? - ANSWER: decimal fractions between 0-1
can the probability of an event be negative? - ANSWER: no
the probability of an event not occurring is equal to what? - ANSWER: q=1-p
what is the addition rule of probability? - ANSWER: the probability of any one of
several particular events occurring is equal to the sum of their individual
probabilities, provided the events are mutually exclusive
what is the multiplication rule of probability? - ANSWER: the probability of two or
more statistically independent events all occurring is equal to the product of their
individual probabilities
the probability that a specific combination of mutually exclusive independent evens
will occur can be determined by what? - ANSWER: binomial distribution
what is a binomial distribution? - ANSWER: one in which there are only two
possibilities, such as yes/no. the binomial distribution gives the probability of
obtaining an exact number of successes in a series of independent trials.
what is a typical medical use of the binomial distribution? - ANSWER: genetic
counseling
what are the four scales of measurement? - ANSWER: nominal
ordinal
interval
ratio
what are nominal scale data? - ANSWER: data divided into qualitative categories or
groups
is there implication of order or ratio for nominal scale data? - ANSWER: no
what are nominal data that fall into only two groups called? - ANSWER: dichotomous
data
