Summer Vocab Flashcards
What is Statistics?
The study of variability
What is variability?
Differences. How things differ. There is variability everywhere…
We all look different, act different, have different preferences.
Statisticians look at these differences.
What are 2 branches of AP STATS?
Inferential and Descriptive
What are DESCRIPTIVE STATS?
Tell me what you got! Describe to me the data that you collected, use pictures or summaries like mean, median, range, etc?
What are INFERENTIAL STATS?
Look at your data, and use that to say stuff about the BIG PICTURE.
Like tasting soup… a little sample can tell you a lot about the big pot of soup (the population)
Compare Descriptive and Inferential STATS
Descriptive tells 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, if it is a survey about liking porridge, the data might be–yes, yes, no, yes, yes.
If it is the number of saltines someone can eat in 30 seconds, the data might be–3, 1, 2, 1, 4, 3, 3, 4.
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 Stats students in my school.”
What is a sample?
A subset of a population, often taken to make inferences about the population. We calculate statistics from samples.
Compare population to sample
Populations are generally large, and samples are small subsets of these population.
We take samples to make inferences about populations.
We use statistics to estimate 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.
Compare DATA-STATISTIC-PARAMETER using a categorical example
Data are individual measures like meal preference: taco, taco, pasta, taco, burger, burger, taco.
Statistics and parameters are summaries.
A statistic would be 42% of sample preferred tacos and a parameter would be 42% of population preferred tacos.
Compare DATA-STATISTIC-PARAMETER using a quantitative example
Data are individual measures, like how long a person can hold their breath: 45 sec, 64 sec, 32 sec, 68 sec.
That is the raw data.
Statistics and parameters are summaries like the average breath holding time in the sample was 52.4 seconds and a parameter would be the average breath holding time in the population was 52.4 seconds.
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 SKHS Stats 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 parameters come from populations.
Statistics come from samples.
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.
