MATH 140 STATISTICS TEST #2 REVISED
| PRACTICE QUESTIONS AND DETAILED
ANSWERS | GRADED A+ |
GUARANTEED SUCCESS
Updated 2026 Questions and Answers | 100% Verified
Exam Prep
,systematic sampling easier than random sampling. the list of elements are counted off and that is every kth
element is taken.
convenience sampling very easy, but the worst technique to use
ex: standing out library to ask questions
cluster sampling divide up population into groups- usually geographically. these groups are called
clusters or blocks. the clusters are randomly selected, and each element in the selected
clusters are used
stratified sampling divide the population into groups called strata. however, this time, it is by some
characteristic not geographically. for instance, the population might be separated into
males and females. a sample is taken from each of these strata using either random,
systematic, or convenience sampling
point estimate center, average
standard error standard deviation of the sample
central limit theorm (CLT) these are assumptions for proportions and means
non-response bias when asking a question, people don't respond
- be careful
- dinner time and someone wants to start a survey
no one will answer
what is the purpose of random selection? is a way to collect data that allows variability in the outcomes. it helps minimize bias and
the sample represents the population
what is the purpose of random assignment? is a way to measure random selection without any bias
create like/similar groups
what does single blind mean? means when a group of people (experimented on) don't know what they receive when
getting a variable. patients don't know if placebo is a treatment
what does double blind mean? a group of people and even the experimenters are unaware of the outcomes of the
experiment. person protoring doesn't know if the administer has placebo or treatment
, what is a control group and why is it used? a group that does not get any alternations
base group to compare to experimental group
what is a placebo? a psychological effect when a person "thinks" he/she got a treatment when it's actually
fake. in some cases, believing that they got treatment is a benefit
random assignment generate numbers on a screen and choose
types of levels of measurement nominal (qualitative vs quantiative)
ordinal data
interval
ratio
population
sample
parameter
statistic
voluntary response sample
correlation and causality
nominal (qualitative vs quantitiate) level of measurement that is something that has names, labels, or categories only
ordinal data arranged in some order. they can be ranked, but no mathematical operations are
meaningful
ratio level of measurement is the interval level with a natural zero starting point examples are
distance, prices, salaries
interval can be arranged in order, but with another property: that the difference between any two
data values is meaningful scale, quantitative, age of all statistics students, annual income,
etc
population a group of phenomena that have something in common
sample smaller group of members of a population selected to represent a population usually
random
parameter characteristic of a population
| PRACTICE QUESTIONS AND DETAILED
ANSWERS | GRADED A+ |
GUARANTEED SUCCESS
Updated 2026 Questions and Answers | 100% Verified
Exam Prep
,systematic sampling easier than random sampling. the list of elements are counted off and that is every kth
element is taken.
convenience sampling very easy, but the worst technique to use
ex: standing out library to ask questions
cluster sampling divide up population into groups- usually geographically. these groups are called
clusters or blocks. the clusters are randomly selected, and each element in the selected
clusters are used
stratified sampling divide the population into groups called strata. however, this time, it is by some
characteristic not geographically. for instance, the population might be separated into
males and females. a sample is taken from each of these strata using either random,
systematic, or convenience sampling
point estimate center, average
standard error standard deviation of the sample
central limit theorm (CLT) these are assumptions for proportions and means
non-response bias when asking a question, people don't respond
- be careful
- dinner time and someone wants to start a survey
no one will answer
what is the purpose of random selection? is a way to collect data that allows variability in the outcomes. it helps minimize bias and
the sample represents the population
what is the purpose of random assignment? is a way to measure random selection without any bias
create like/similar groups
what does single blind mean? means when a group of people (experimented on) don't know what they receive when
getting a variable. patients don't know if placebo is a treatment
what does double blind mean? a group of people and even the experimenters are unaware of the outcomes of the
experiment. person protoring doesn't know if the administer has placebo or treatment
, what is a control group and why is it used? a group that does not get any alternations
base group to compare to experimental group
what is a placebo? a psychological effect when a person "thinks" he/she got a treatment when it's actually
fake. in some cases, believing that they got treatment is a benefit
random assignment generate numbers on a screen and choose
types of levels of measurement nominal (qualitative vs quantiative)
ordinal data
interval
ratio
population
sample
parameter
statistic
voluntary response sample
correlation and causality
nominal (qualitative vs quantitiate) level of measurement that is something that has names, labels, or categories only
ordinal data arranged in some order. they can be ranked, but no mathematical operations are
meaningful
ratio level of measurement is the interval level with a natural zero starting point examples are
distance, prices, salaries
interval can be arranged in order, but with another property: that the difference between any two
data values is meaningful scale, quantitative, age of all statistics students, annual income,
etc
population a group of phenomena that have something in common
sample smaller group of members of a population selected to represent a population usually
random
parameter characteristic of a population
