STAT 1040 Exam 1 Review Questions With
Complete Answers
What is the main difference between quantitative and categorical variables? - ANSWER
Quantitative variables can be averaged while categorical variables cannot
What do parameters describe? - ANSWER Population characteristics
What is a statistic? - ANSWER A number that describes a sample
What a Simple Random Sample (SRS)? - ANSWER Size (n) consists of (n) individuals from
the population chosen in a way that each individual has an equal chance of being
selected for the sample
What is a stratified sample? - ANSWER Divide a population into distinct groups of
individuals (strata) then take a separate SRS in each stratum to compile a complete
sample
What is a convenience sample? - ANSWER Selection of individuals which are easiest to
reach
What is a voluntary response sample? - ANSWER A sample that chooses itself by
responding to general appeal
, What are examples of voluntary response samples? - ANSWER Write-in or call-in polls
What are the two properties of random digits? - ANSWER 1) Each entry is equally likely
to be any of the 10 digits 0 through 9
2) The entries are independent of each other
What is a confidence statement? - ANSWER A fact used to say how much we can trust
the results of a sample
What are the two parts of a confidence statement? - ANSWER Margin of error and level
of confidence
How do you obtain a smaller margin of error with the same level of confidence? -
ANSWER Take a larger sample
What is the usual level on confidence? - ANSWER 95%
How can you reduce bias? - ANSWER Use a SRS
How can you reduce variability of a SRS? - ANSWER Use a larger sample
Complete Answers
What is the main difference between quantitative and categorical variables? - ANSWER
Quantitative variables can be averaged while categorical variables cannot
What do parameters describe? - ANSWER Population characteristics
What is a statistic? - ANSWER A number that describes a sample
What a Simple Random Sample (SRS)? - ANSWER Size (n) consists of (n) individuals from
the population chosen in a way that each individual has an equal chance of being
selected for the sample
What is a stratified sample? - ANSWER Divide a population into distinct groups of
individuals (strata) then take a separate SRS in each stratum to compile a complete
sample
What is a convenience sample? - ANSWER Selection of individuals which are easiest to
reach
What is a voluntary response sample? - ANSWER A sample that chooses itself by
responding to general appeal
, What are examples of voluntary response samples? - ANSWER Write-in or call-in polls
What are the two properties of random digits? - ANSWER 1) Each entry is equally likely
to be any of the 10 digits 0 through 9
2) The entries are independent of each other
What is a confidence statement? - ANSWER A fact used to say how much we can trust
the results of a sample
What are the two parts of a confidence statement? - ANSWER Margin of error and level
of confidence
How do you obtain a smaller margin of error with the same level of confidence? -
ANSWER Take a larger sample
What is the usual level on confidence? - ANSWER 95%
How can you reduce bias? - ANSWER Use a SRS
How can you reduce variability of a SRS? - ANSWER Use a larger sample
