Summer Work Flashcards
What is Statistics?
The study of variability
What is variability?
Differences and how things differ
What are 2 branches of AP STATS?
inferential and descriptive
What are descriptive stats?
Describing what you see in statistics
What are inferential stats?
Using information from a sample to make an inference about an entire population
Compare descriptive and inferential stats
Descriptive explains the data you have inferential uses that data to say something about the entire population
What is data?
Collected information
what is a population?
The group you’re interested in studying
what is a sample?
A subset of a population often taken to make inferences about the population
compare population to sample
Populations are the whole, Sample is the subset of the whole
Compare data to statistics
Data is the individual little things we collect. Statistics is the average of the data in a sample.
Compare data to parameters
Data is each little bit of information collected. Parameter is data from each member of a population averaged.
what is a parameter?
A numerical summary of a population
What is a statistic?
A numerical summary 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 the 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 the cars. The data is the wait time of each individual car. You take that data and find the average that averages called a statistic, and you use that to make an inference about the true parameter.
Compare data-statistic-parameter using categorical example
Data are individual measures like meal preference. Statistics and parameters are summaries of the data. A statistic would be 42% of sample preferred tacos. A parameter would be 42% of population prefer tacos.
compare data-statistic-parameter using quantitative example
Data are individual measures that can be averaged. Statistics and parameters are summaries of the data like ‘an average breath holding time of 45.2.’ Statistics cover samples while parameters cover population.
What is a census?
getting Information from every member of the population
Does a census make sense?
It is OK for small populations but impossible for larger populations
What is the difference between a parameter and a Statistic?
Both are a single number summarizing a larger group of numbers, But a parameter comes from a population and a statistic comes from a sample.
If I take a random sample of 20 hamburgers from five guys and count the number of pickles on a bunch of them and one of them had nine pickles, then the number of nine from that burger would be called what?
A datum, or a data value
If I take a random sample of 20 hamburgers from five guys and count the number of pickles on a bunch of them and the average number of pickles was 9.5, then 9.5 is considered a what?
A statistic
If I take a random sample of 20 hamburgers from five guys and count the number of pickles on a bunch of them and I do this because I want to know the true average number of pickles on a burger at five guys the true average number of pickles is considered a what?
parameter