STATS EXAM QUESTIONS AND ANSWERS
The term statistics can have two meanings. Describe both meanings.
a.Statistics is the science of collecting, organizing, and interpreting data and statistics is
always definitive.
b.Statistics is the science of collecting, organizing, and interpreting data and statistics
are the data (numbers or other pieces of information) that describe or summarize
something.
c.Statistics is a type of algebra and statistics are variables in equations.
d.Statistics is information used to make graphs and statistics are always numbers. -
Answers- b
The Population is - Answers- complete set of people or things being studied,
a population parameter is - Answers- a number that describes a characteristic of the
population
a sample is the - Answers- set of people or things from which the data are obtained,
sample statistic is - Answers- a number that describes a characteristic of a sample
raw data are - Answers- the individual measurements collected.
Margin of Error - Answers- is used to describe the range of values likely to contain a
population parameter and is added to and subtracted from a
sample statistic to establish a confidence interval
Confident interval - Answers- is used to estimate a population parameter.
from (sample statistic-margin of error)
to (sample statistic+margin of error)
Basic Steps in a Statistical Study 1 - Answers- State the goal of your study precisely
2 - Answers- Choose a representative sample from the population
3 - Answers- Collect raw data from the sample and summarize these data
4 - Answers- Use the sample statistics to infer the population parameters
5 - Answers- draw conclusions
, There is no doubt that Johnson won the election, because an exit poll showed that she
received 54% of the vote and the margin of error is only 3 percentage points. (Assume
that all the people in the poll answered truthfully.)
a.The statement makes sense, because 54% is greater than 50%.
b.The statement does not make sense, because there is always a possibility that a
population parameter is not contained in the confidence interval determined by a
sample statistic and a margin of error.
c.the statement does not make sense, because there is the possibility that Johnson lost
the election, and the result is still within the margin of error.
d.The statement makes sense, because all of the values contained in the confidence
interval, determined by the sample statistic and the margin of error, give Johnson a
majority (over 50% of the vote). - Answers- b
A pollster plans to improve survey results by only conducting polls in which the margin
of error is zero.
a.The statement does not make sense. The margin of error is always a fixed fraction of
the sample statistic
b.The statement makes sense. Any value can be chosen for the margin of error.
c.The statement makes sense. A margin of error of zero implies that there is no
uncertainty in a survey result. This could happen if the entire population was surveyed.
d.The statement does not make sense. A margin of error of zero implies that there is no
uncertainty in a survey result. This could happen only if the entire population was
surveyed, rather than just a sample. - Answers- d
One study of heart disease involved treating male physicians with daily doses of aspirin.
Because the study concluded that aspirin helps males avoid heart disease, it follows
that females can also avoid heart disease by taking aspirin.
a.The statement makes sense. Inferences about the population of humans should apply
to both males and females.
b.The statement does not make sense. Inferences about the population of male
physicians can only apply to all males.
c.The statement makes sense. Inferences about one population should apply to all
populations.
The term statistics can have two meanings. Describe both meanings.
a.Statistics is the science of collecting, organizing, and interpreting data and statistics is
always definitive.
b.Statistics is the science of collecting, organizing, and interpreting data and statistics
are the data (numbers or other pieces of information) that describe or summarize
something.
c.Statistics is a type of algebra and statistics are variables in equations.
d.Statistics is information used to make graphs and statistics are always numbers. -
Answers- b
The Population is - Answers- complete set of people or things being studied,
a population parameter is - Answers- a number that describes a characteristic of the
population
a sample is the - Answers- set of people or things from which the data are obtained,
sample statistic is - Answers- a number that describes a characteristic of a sample
raw data are - Answers- the individual measurements collected.
Margin of Error - Answers- is used to describe the range of values likely to contain a
population parameter and is added to and subtracted from a
sample statistic to establish a confidence interval
Confident interval - Answers- is used to estimate a population parameter.
from (sample statistic-margin of error)
to (sample statistic+margin of error)
Basic Steps in a Statistical Study 1 - Answers- State the goal of your study precisely
2 - Answers- Choose a representative sample from the population
3 - Answers- Collect raw data from the sample and summarize these data
4 - Answers- Use the sample statistics to infer the population parameters
5 - Answers- draw conclusions
, There is no doubt that Johnson won the election, because an exit poll showed that she
received 54% of the vote and the margin of error is only 3 percentage points. (Assume
that all the people in the poll answered truthfully.)
a.The statement makes sense, because 54% is greater than 50%.
b.The statement does not make sense, because there is always a possibility that a
population parameter is not contained in the confidence interval determined by a
sample statistic and a margin of error.
c.the statement does not make sense, because there is the possibility that Johnson lost
the election, and the result is still within the margin of error.
d.The statement makes sense, because all of the values contained in the confidence
interval, determined by the sample statistic and the margin of error, give Johnson a
majority (over 50% of the vote). - Answers- b
A pollster plans to improve survey results by only conducting polls in which the margin
of error is zero.
a.The statement does not make sense. The margin of error is always a fixed fraction of
the sample statistic
b.The statement makes sense. Any value can be chosen for the margin of error.
c.The statement makes sense. A margin of error of zero implies that there is no
uncertainty in a survey result. This could happen if the entire population was surveyed.
d.The statement does not make sense. A margin of error of zero implies that there is no
uncertainty in a survey result. This could happen only if the entire population was
surveyed, rather than just a sample. - Answers- d
One study of heart disease involved treating male physicians with daily doses of aspirin.
Because the study concluded that aspirin helps males avoid heart disease, it follows
that females can also avoid heart disease by taking aspirin.
a.The statement makes sense. Inferences about the population of humans should apply
to both males and females.
b.The statement does not make sense. Inferences about the population of male
physicians can only apply to all males.
c.The statement makes sense. Inferences about one population should apply to all
populations.
