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 presences statisticians look at these differences.
What are two 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(population)
Compare Descriptive and inferential STATS
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 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 secs the data may be 3 1 2 1 4 3 3 4
What is a population?
The group you’re interested in.
What is a sample
A subset population often 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 the population
Data to Statistics
Data is each little bit of info collected from the subjects 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
Parameter
A numerical summary of a population like a mean median range of a population
Statistic
A numerical summary of a sample like a mean median range of a sample
Data-Statistic-Parameter categorical example
Data are individual measures like meal preference taco taco pasta taco burger burger taco statistics and parameter are summaries. A statistic would be 42% of sample preferred tacos and a parameter would be 42% of population preferred tacos.
D-S-P 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
Census
Like 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 me nystroms students) but impossible if you want to survey all US teens.
Parameter vs Statistic
Both are single number summarizing a larger group of numbers but pppp parameters come from pppp populations sss statistics come from ssss statistics
Sample vs census
Sample from small population census from entire population
Random variables
If you randomly choose people from a list then their hair color height weight and any other data collected can be considered random variables
Quantities vs Categorical variables
Quantities numerical measures categorical are categories like eye color
Quantitative variable
Numerical height age number of cars sold
Categorical variable
Like categories blonde female yes no etc
Categorical is also called
Qualitative
Frequency
How often something goes up
Mode
Most common
Median
Middle number
Mean
Average
Who chases the tail
The mean
