Beginning AP Stats Vocab Flashcards
What is statistics?
The study of variability
What is variability?
Differences (how things differ). Examples include differences in looks, behaviors, and preferences—all of which are studied by statisticians.
What are the two branches of AP Stats?
Inferential and Descriptive
What are DESCRIPTIVE stats?
Stats used to describe data using pictures and summaries like mean, median, and mode; facts
What are INFERENTIAL stats?
Stats used to generalize data (like how one sample describes the rest of the population); predictions
Compare DESCRIPTIVE and INFERENTIAL stats
Descriptive describes the data set you have, and inferential uses data to say something about the greater population
What is data?
Any collected information (each little measurement, generally)
What is a population?
A group from which data is collected
What is a sample?
A subset of a population taken to make inferences about the population in general. Statistics are calculated from samples
Compare population to sample
Populations are usually large, and samples are small subsets of populations. We take samples to make inferences about populations. We use statistics to estimate parameters.
Compare data to statistics
Data is every little bit of information collected from subjects within a population that are summarized in different ways (such as finding the mean in a group of data). If it is a sample, then the mean is called a “statistic”; if we have data from each member of a population, then the mean is called a “parameter”
Compare data to parameters
Data is every little bit of information collected from subjects within a population that are summarized in different ways (such as finding the mean in a group of data). If the data is from a sample, then the mean is called a “statistic”; if we have data from each member of a population, then the mean is called a “parameter”
What is a parameter?
A numerical summary of a population. The mean, median, mode, and range of a population are considered parameters
What is a statistic?
A numerical summary of a sample. The mean, median, mode, and range of a sample are considered statistics
We are curious about the average wait time at Dunkin’ Donuts drive-thru in your neighborhood. You randomly sample cars one afternoon and find the average wait time is 3.2 minutes. What is the parameter? What is the statistic? What is the parameter of interest? What is the data?
The parameter is the true average wait time at 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 from the random sample. The parameter of interest is the same 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, such as “3.8 min 2.2 min, .8 min, 3 min.” You take that data and find the average, that average is called the “statistic,” and you use that to make an inference about the true parameter.
Compare data, parameter, and statistic using a categorical example
Data are individual measures, like meal preference (taco, taco, burger, pizza, burger, taco, pizza), parameters and statistics are summaries. A statistic could be “42% of the sample prefer tacos” and a parameter could be “42% of the population prefer tacos”
Compare data, parameter, and statistic using a quantitative example
Data are individual measures, like how long a person can hold their breath (45 sec, 22 sec, 52 sec, 48 sec). That is the raw data. Statistics and parameters are summaries of the data; a sample could be “the average breath holding time in the sample was 52.4 seconds,” and a parameter could be “the average breath holding time in the population was 52.4 seconds”
What is a census?
Like a sample of the entire population, but you get information from EVERY member of the population
Does a census make sense?
A census is okay for small populations (like a classroom of students), but it is impossible if you want to survey “all U.S. teens”
What is the difference between a parameter and a statistic?
BOTH ARE A SINGLE NUMBER SUMMARIZING A LARGE GROUP OF NUMBERS…. but parameters come from POPULATIONS (think P for pop.), and statistics come from SAMPLES (think S for samp.)
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 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 the ______.
statistic (a summary of a sample)