Summer Vocab Flashcards
Remember these
What is statistics?
Study of variability
Variability?
Differences, or how things are different
2 branches of statistics?
inferential and descriptive
Descriptive
Describing the data… i.e. mean, median, mode, range
Inferential
Using the data to talk about the bigger picture
Differences between descriptive and inferential
Descriptive explains the data while inferential uses the data to say something about the entire population
What is data?
Any collected information
What is a population?
The group of people that you are interested in
What is a sample?
The portion of the population that data is being taken from. Statistics come from a sample
Compare population to sample
A population is a generally a large group while a sample is a subset of that population. We use samples to make inferences about the population, and we use the population to make parameters.
Compare data to statistics
Data is each little bit of information collected from the subjects…. They are the
INDIVIDUAL little things we collect… we summarize them by, for example, finding
the mean of a group of data. If it is a sample, then we call that mean a “statistic” if
we have data from each member of population, then that mean is called a
“parameter”
Compare data to parameters
Data is each little bit of information collected from the subjects…. They are the
INDIVIDUAL little things we collect… we summarize them by, for example, finding
the mean of a group of data. If it is a sample, then we call that mean a “statistic” if
we have data from each member of population, then that mean is called a
“parameter”
What is a parameter?
A numerical summary of a population. Like a mean, median, range… of a
population
What is a statistic?
A numerical summary of a sample. Like a mean, median, range… of a sample.
We are curious about the average wait time at a Dunkin Donuts drive through in your neighborhood. You randomly sample cars one afternoon and find the average wait time is 3.2 minutes. What is the population parameter? What is the statistic? What is the parameter of interest? What is the data?
The parameter is the true average wait time at that Dunkin Donuts. This is a
number you don’t have and will never know. The statistic is “3.2 minutes.” It is the
average of the data you collected. The parameter of interest is the same thing as
the population parameter. In this case, it is the true average wait time of all cars.
The data is the wait time of each individual car, so that would be like “3.8 min, 2.2
min, .8 min, 3 min”. You take that data and find the average, that average is called
a “statistic,” and you use that to make an inference about the true parameter.