### Distinguish between a population and a sample

```Things you should know from Chapter 1
Distinguish between a population
and a sample
Examples:
Identify the population and sample in each study
1. Thirty-eight nurses working in the San Francisco area were
surveyed concerning their opinions of managed health
care.
2. A survey of 39 credit cards found that the average annual
percentage rate is 12.83%.
Things you should know from Chapter 1
Distinguish between a population
and a sample
Examples:
Identify the population and sample in each study
1. Thirty-eight nurses working in the San Francisco area were surveyed
concerning their opinions of managed health care. Population – opinions
of all nurses in San Fran area. Sample – opinions of the 38 nurses
surveyed.
2.
A survey of 39 credit cards found that the average annual percentage rate
is 12.83%. Population – annual percentage rates of all credit cards.
Sample – the percentage rates of the 39 credit cards surveyed.
Things you should know from Chapter 1
Distinguish between a parameter
and a statistic
Examples:
Identify if each describes a parameter or a statistic.
1. The 2009 team payroll of the Philadelphia Phillies was
\$113,004,046.
2.
In a survey of 752 adults in the US, 42% think there should be a law
that prohibits people from talking on cell phones in public places.
3.
In a recent study of math majors at a university, 10 students were
minoring in physics.
Things you should know from Chapter 1
Distinguish between a parameter
and a statistic
Examples:
Identify if each describes a parameter or a statistic.
1. The 2009 team payroll of the Philadelphia Phillies was
\$113,004,046. Parameter.
2.
In a survey of 752 adults in the US, 42% think there should be a law
that prohibits people from talking on cell phones in public places.
Statistic.
3.
In a recent study of math majors at a university, 10 students were
minoring in physics. Parameter.
Things you should know from Chapter 1
Distinguish between descriptive
statistics and inferential statistics
Example:
1. A survey of 39 credit cards found that the
average annual percentage rate is 12.83%.
- Which part of this study represents the
descriptive branch of statistics. Make an inference
based on the results of the study.
Things you should know from Chapter 1
Distinguish between descriptive
statistics and inferential statistics
Example:
1. A survey of 39 credit cards found that the average
annual percentage rate is 12.83%.
- Which part of this study represents the
descriptive
branch of statistics. 39 credit cards surveyed had an average
annual percentage rate of 12.83%. Make an inference based
on the results of the study. The average annual percentage
rate of all credit cards is 12.83%.
Things you should know from Chapter 1
Distinguish between qualitative and
quantitative data.
Examples:
1. The monthly salaries of the employees at an
accounting firm.
2. The social security numbers of the employees at
an accounting firm.
3. The marital statuses of all professional golfers.
Things you should know from Chapter 1
Distinguish between qualitative and
quantitative data.
Examples:
1. The monthly salaries of the employees at an accounting
firm. Quantitative.
2. The social security numbers of the employees at an
accounting firm. Qualitative.
3. The marital statuses of all professional golfers.
Qualitative.
Things you should know from Chapter 1
Classify data according to the four
levels of measurement.
Examples:
1. A list of badge numbers of police officers at a
precinct. (note: badge numbers can identify
officer rank).
2. The horsepowers of racing car engines.
3. The top 10 grossing films released in 2010.
4. The years of birth for the runners in the Boston
marathon.
Things you should know from Chapter 1
Classify data according to the four
levels of measurement.
Examples:
1. A list of badge numbers of police officers at a precinct.
(note: badge numbers can identify officer rank).
Ordinal.
2. The horsepowers of racing car engines. Ratio.
3. The top 10 grossing films released in 2010. Ordinal.
4. The years of birth for the runners in the Boston
marathon. Interval.
Things you should know from Chapter 1
Know how data are collected – by doing an
observational study, performing experiment, using a
simulation, using a survey, or taking a census.
Examples:
Which method of data collection would you use:
1. A study on the effect of low dietary intake of
2. A study of charitable donations of the CEOs in
Syracuse, New York.
3. A study of college professors’ opinions on
teaching classes online.
Things you should know from Chapter 1
Know how data are collected – by doing an
observational study, performing experiment, using a
simulation, using a survey, or taking a census.
Examples:
Which method of data collection would you use:
1. A study on the effect of low dietary intake of vitamin C
2. A study of charitable donations of the CEOs in Syracuse,
New York. Census. (or survey – but census would be
better)
3. A study of college professors’ opinions on teaching
classes online. Survey.
Things you should know from Chapter 1
Know good ways to design an
experiment.
- Sample size, sampling methods, control/placebo
with blind studies, replication
Things you should know from Chapter 1
Identify/describe the different sampling
techniques: simple random sampling, stratified
sampling, cluster sampling, convenience
sampling, and systematic sampling
Examples:
Identify the sampling technique. Explain your decision.
1. A student asks 18 friends to participate in a psychology experiment. Convenience –
because it is convenient to non-randomly choose your friends. (could be other
answers, as long as they are correctly supported)
2. A pregnancy study in Cebu, Philippines randomly selects 33 communities form the
Cebu metropolitan area, then interviews all available pregnant women in these
communities. Cluster – several groups were randomly selected and all members of
those groups were interviewed.
3. Law enforcement officials stop and check the driver of every third vehicle for blood
alcohol content. Systematic – a predetermined system to the sampling.
4. Twenty-five students are randomly selected from each grade level at a high school
and surveyed about their study habits. Stratified – population divided into groups
(grade levels) and students randomly selected from each group.
Things you should know from Chapter 1
Identify a biased sample
Examples:
Identify a bias that might occur in the following
studies:
1. A student asks 18 friends to participate in a
psychology experiment.
2. Law enforcement officials stop and check the
driver of every third vehicle for blood alcohol
content.
Things you should know from Chapter 1
Identify a biased sample