Vocab 1 Flashcards
What is statistics?
The study of variability.
What is variability?
How things differ from each other.
What are the 2 branches of AP STATS ?
Inferential and descriptive.
What are inferential stats?
Look at your data and use that to say stuff about the big picture.
What are descriptive stat?
Describing the data you collected using pictures summary like mean median range etc.
Compare descriptive and inferential stat
Descriptive explains you about the data that you have, inference uses that data you have to try to say something about an entire population.
What is data?
Any collected information. Generally each little measurement like a survey.
What is a population?
The group you’re interested in. Sometimes it’s big like all teenagers in the US other times it is small like all AP Stat students in my school
What is a sample
Subset of a population often taken to make inferences about the population
Compare population to sample
Population are generally large and samples are subset of these population. We take samples to make inferences about the population. We use statistics to estimate parameters.
Compare data to statistics
Data is each little bit of information collected from the subject. The mean of a sample is called statistic. The mean of the population is called the parameter.
What is statistic
A numerical summary of a sample
What is a parameter
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 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.
Compare DATA-STATISTIC- PARAMETER using categorical example
Data are individual measures… like meal preference: “taco, taco, pasta, taco, burger, burger, taco”..A Statistics and Parameters are summaries, A statistic would be “42% of sample preferred tacos” and a parameter would be “42% of population preferred taco.
What is a census?
Like a sample of the entire population, you get information from every member of the population.
Does a census make sense?
A census is ok for small populations (like Mr. Nystrom’s students) but impossible if you want to survey all US teens.
What is the difference between a parameter and a statistic?
BOTH ARE A SINGLE NUMBER SUMMARIZING A LARGER GROUP OF NUMBERS…. But pppp parameters come from pppp populations… sss statistics come from ssss 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 9 pickles, then the number 9 from that burger would be called ?
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 ?
Statistic ( it is the summary of 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 l 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 ?
Parameter, one number summary of the population. The truth. AKA the parameter of interest.
What is the difference between a sample and a census?
census is you get info from the entire population. You can get a parameter from a census, but only a statistic from a sample.