AP Statistics summer vocabulary

Question 1

What is Statistics

Answer 1

The study of variablilty

Question 2

What is Variability?

Answer 2

Differences… how things differ. There is variability everywhere. We all look different, act different, have different preferences… Statisticians look at these differences.

Question 3

What are two branches of AP STATS?

Answer 3

Inferential and Descriptive

Question 4

What are DESCRIPTIVE STATS?

Answer 4

Tell me what you got! Describe to me the data that you collected, use pictures or summaries like mean, median, range, etc…

Question 5

What are INFERENTIAL STATS?

Answer 5

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)

Question 6

Compare Descriptive and Inferential STATS

Answer 6

Descriptive explains to you about the data that you have, inference uses the data that you have to try to say something about an entire population.

Question 7

What is Data?

Answer 7

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”

Question 8

What is population?

Answer 8

The group you’re interested in. Sometimes it’s big, like”all teenagers in the US” other times it,s small, like “all AP students in my school.”

Question 9

What is a sample?

Answer 9

A subset of a population, often taken to make inferences about the population. We calculate stats from samples.

Question 10

Compare population to sample

Answer 10

Populations are generally large, and samples are small subsets of a population. We take samples to make inferences about population. We calculate stats to estimate parameters.

Question 11

Compare data to statistics

Answer 11

Data is each little bit of information collected form subjects… They are the INDIVIDUAL little things we collect… we summarize them by, fer 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 a population, then that means is called a “parameter.”

Question 12

Compare data to parameters

Answer 12

Data is each little bit of information collected from 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 that we call that mean a statistic if we have data from each member of population that mean is called a parameter

Question 13

What is a parameter?

Answer 13

A numerical summary of a population. Like a mean, median, range… of a population

Question 14

What is a statistic?

Answer 14

A numerical study of a sample. Like a mean, median, range… of a sample.

Question 15

We are curios about the average wait time at a Dunkin Doughnuts drive through in you neighborhood. You randomly sample cars one afternoon to find 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?

Answer 15

The parameter is the true avg. wait time at Dunkin. This is a number you don’t have and will never know . The statistic is 3.2 mins. It is the avg. 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. You take the data and find the average, the average is called a statistic, and you use that to make an inference about the true parameter.

Question 16

Compare DATA-STATISTIC-PARAMETER using categorical (qualitative) example

Answer 16

Data are individual measures… like meal preference: “taco, taco, pasta, burger, taco.” Statistics and Parameters are summaries. A Statistic would be “42% of the sample prefer tacos.” and a parameter would be “43% of the population prefer tacos.”

Question 17

Compare DATA-STATISTIC-PARAMETER using quantitative (numerical) example

Answer 17

Data; individual measures like how long one can hold breath (in seconds): “45, 64, 32, 68.” That is the raw data. Stats and parameters are summaries. (stats are based on sample, parameters are based on population.)

Question 18

What is frequency?

Answer 18

How often something comes up.

Question 19

What is frequency distribution?

Answer 19

A table, or chart, that shows how often certain values or categories occur in a data set.

Question 20

What is meant by relative frequency?

Answer 20

The PERCENT of time something comes up; relevancy (frequency/total)

Question 21

How do you find relative frequency?

Answer 21

Just divide frequency by TOTAL.

Question 22

What is meant by cumulative frequency?

Answer 22

ADD up the frequencies as you go. Suppose you are selling 25 pieces of candy. You sell 10 the first hour, 5 seconds, 3 the third, and 7 the last hour, the cumulative frequency would be 10, 15, 18, and 25

Question 23

What is a census?

Answer 23

Like a sample of the entire population, you get information from every memeber of the population

Question 24

Does a census make sense?

Answer 24

A census is ok for small populations (Like Mr. Nystrom’s students) but impossible if you want to survey “all US teens”

Question 25

What is the difference between a parameter and a statistic?

Answer 25

BOTH ARE A SINGLE NUMBER SUMMARIZING A LARGER GROUP OF NUMBERS. but ppp Parameters come from ppp Populations, and sss Statistics come from sss Samples.

Question 26

What do we sometimes call a categorical variable?

Answer 26

qualitative

Question 27

What is quantitative data?

Answer 27

The actual numbers gathered from each subject. 211 pounds. 67 beats per minute.

Question 28

What is categorical data?

Answer 28

The actual individual category from a subject, like “blue” or “female”

Question 29

What is a random sample?

Answer 29

When you choose a sample by rolling dice, choosing names from a hat, or other REAL RANDOMLY generated sample. Humans can’t really do this well without the help of a calculator, cards, dice, or slips of paper.

Question 30

Data or Datum?

Answer 30

datum is singular data is plural

Question 31

Make a guess as to what relative cumulative frequency

Answer 31

the ADDED up PERCENTAGES

Question 32

What is the difference between a bar chart and a histogram?

Answer 32

Bar charts-for categorical data (bars don’t touch)

Histograms- for quantitative data (bars touch)

Question 33

What is the mean?

Answer 33

The old average we used to calculate. It is the balancing point of the histogram.

Question 34

What is the median?

Answer 34

The middlest number, it splits area in half (always in the position (n+1)/2 )

Question 35

What is the mode?

Answer 35

The most common, or the peaks of a histogram. We often use mode with categorical data

Question 36

What symbols do we use for population mean and sample mean?

Answer 36

Mu (μ) for population mean (parameter), x bar (x̅) for sample mean (statistic)

Question 37

What is the difference between a population mean and a sample mean?

Answer 37

a population mean is a parameter, a sample mean is a statistic. we use sample statistics to make inferences about population parameters.

Question 38

How can you remember the difference between mean and median when looking at a histogram.

Answer 38

The mean is the balancing point of the histogram, the median splits the area of a histogram in half.

Question 39

Why don’t we always use the mean, we’ve been calculating it all of our life?

Answer 39

It’s not RESILIENT, it’s impacted by skew-ness and outliers (an unnaturally large or small data value)

Question 40

When do we often use mode?

Answer 40

With categorical variables. For instance, to describe the avg. teenagers preference, we often speak of what “most” students chose, which is mode. It also tells the number of bumps in a histogram for quantitative data (unimodal, bimodal, etc…)

Question 41

When we say the avg. teenager are we talking mean, median, or mode?

Answer 41

Depends, if we’re talking height it may be mean, if we’re talking parental income, probably median, if we’re talking music preference, we’d likely use the mode to talk about the avg. teen.

Question 42

If I take a random sample of 20 hamburgers from 5 Guys and count the number of pickles on a bunch of them, and one of the has 9 pickles, then the number 9 from that burger would be called ____?

Answer 42

A datum or data.

Question 43

If I take a random sample of 20 hamburgers from 5 Guys and count the number of pickles on a bunch of them, and the avg. number of pickles was 9.5, then 9.5 is considered a ______?

Answer 43

A statistic (a summary of a sample)

Question 44

If I take a random sample of 20 hamburgers from 5 Guys and count the number of pickles on a bunch of them, and I do this because I want to know the true avg. number of pickles on a burger at 5 Guys , the true avg. number of pickles is considered a ________?

Answer 44

A parameter, a one number summary of the population. The truth. AKA the parameter of interest.

Question 45

What is the difference between a sample and a census?

Answer 45

With a sample, you get info from a small part of the population. In a census, you get info from the entire population. You can get a parameter from a census, but only a statistic from a sample.

Question 46

Use the following words in one sentence: Population, parameter, census, sample, data, statistics, inference, population of interest.

Answer 46

I was curious about a population parameter, but a census was to costly so I decided to choose a sample, collect some data, calculate a statistic and use that statistic to make an inference about the population parameter (aka the parameter of interest).

Question 47

What are random variables?

Answer 47

If you randomly choose people from a list, then their hair color, height, weight and any other data collected from them can be considered random variables.

Question 48

What is the difference between quantitative and categorical variables?

Answer 48

Quantitative variables are numerical measures, like height or IQ. Categorical variables are qualities, or categories, like eye color and music preference.

Question 49

What is a quantitative variable?

Answer 49

Quantitative variables are numeric like height, age, SAT score, etc.

Question 50

What is a categorical variable?

Answer 50

Categorical variables are qualities, or categories: Blonde, prefers Hip Hop, Female, yes, no, etc.

Question 51

If you are tasting soup, then the flavor of each individual thing in the spoon is the 1)____, the entire spoon is a 2)_____. The flavor of all that stuff together is like the 3)____ and you use that to 4)____ about the flavor of the entire pot of soup, which would be the 5)_____.

Answer 51

1) Data
2) Sample
3) Statistic
4) Make an inference
5) Parameter

(Notice you are interested in the parameter to begin with, which is why you took the sample.)

Question 52

What is the difference between quantitative and categorical data?

Answer 52

Data from quantitative variables are numbers.

Data from categorical variables are usually words.

Question 53

What is the difference between discrete and continuous variables?

Answer 53

Discrete can be counted like number of cars sold, they are generally integers (you wouldn’t sell 9.3 cars), while Continuous would be something like weight of a guinea pig, say 1.678 lbs.