Summer Vocab

Question 1

What is Statistics?

Answer 1

The study of variability

Question 2

What is variability?

Answer 2

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 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 tatse tells you about the whole pot….. a sample can tell you a lot about an entire population…

Question 6

Compare Descriptive and Inferential Stats

Answer 6

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

Question 7

What is data?

Answer 7

Any collected information.

Question 8

What is a population?

Answer 8

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

Question 9

What is a sample?

Answer 9

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

Question 10

Compare population to sample

Answer 10

Populations are generally large, and samples are small subsets of these populations. We take smaples to make inferences about populations. We use statistics to estimate parameters.

Question 11

Compare data to statistics

Answer 11

Data is each little bit of information collected from the subjects…. they are the INDIVIDUAL little things we collect…. Statistics are when we summarize data 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 a population, then that mean is called a “parameter”.

Question 12

Compare data to parameters

Answer 12

Data is each little bit of information collected from the subjects…. They are the INDIVIDUAL little things we collect… parameters are the numbers that summarize an entire population.

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 summary of a sample. Like a mean, median, range… of a sample.

Question 15

We are curious about the average wait time at a Dunkin Donuts druve through in your neighborhood. You randomly sample cars one afternoon and find the average 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 average wait time at that Dunkin Donuts. This is a number you dont 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 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.

Question 16

Compare Data-Statistic-Parameter using categorical example

Answer 16

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 preffered tacos”.

Question 17

Compare Data-Statistic-Parameter using quantitative example

Answer 17

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”

Question 18

What is a census?

Answer 18

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

Question 19

Does a census make sense?

Answer 19

A census is ok for small populations but impossible if you want to survey “all US teens”

Question 20

What is the difference between a parameter and a statistic?

Answer 20

BOTH ARE A SINGLE NUMBER SUMMARIZING A LARGER GROUP OF NUMBERS…. But pppp parameters come from pppp populations…. sss statistics come from sss statistics.

Question 21

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, the the number 9 from that burger would be called ____?

Answer 21

A datum, or a data value.

Question 22

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 ____?

Answer 22

Statistic. (It is a summary of a sample.)

Question 23

If i take a random sample of 20 hamburgers from Five Guys and count the number of pickles on a bunch of them…. and I 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 ____?

Answer 23

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

Question 24

What is the difference between a sample and a census?

Answer 24

With a sample, you get information 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 25

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

Answer 25

I was curious about a population parameter, but a census was too 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 26

If you are tasting soup.. Then the flavor of each individual thing in the spoon is the _________, the entire spoon is a _________… The flavor of all that stuff together is like the ________. And you use that to _________ about the flavor of the entire pot of soup, which would be the ___________.

Answer 26

If you are tasting soup.. Then the flavor of each individual thing in the spoon is the DATA, the entire spoon is a SAMPLE… The flavor of all that stuff together is like the STATISTIC. And you use that to MAKE AN INFERENCE about the flavor of the entire pot of soup, which would be the PARAMETER.

Question 27

What are random vatiables?

Answer 27

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 28

What is the difference between quantitavive and categorical variables?

Answer 28

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

Question 29

What is the difference between quantitative and categorical data?

Answer 29

The data is the actual gathered meausurements. So if it is eye color, then the data would look like this “blue,brown, brown, brown, blue, green, blue, brown,… etc”. The data from categorical variables are usually words, often it is simply “yes,yes,yes,no,yes,no”. If it was weight, then the data would be quantitative like “125,155, 223,178, 222, etc..” the data from quantitative variables are numbers.

Question 30

What is frequency?

Answer 30

How often something comes up

Question 31

Data or datum?

Answer 31

Datum is singular. Data is plural.

Question 32

What is a frequency distribution?

Answer 32

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

Question 33

What is meant by realative frequency?

Answer 33

The percent of time something comes up (frequency/total)

Question 34

How do you find relative frequency?

Answer 34

Just divide frequency by TOTAL…

Question 35

What is meant by cumulative frequency?

Answer 35

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

Question 36

What is cumulative frequency?

Answer 36

It is the added up percentages

Question 37

What is the mean?

Answer 37

The old average. The balancing point of the histogram.

Question 38

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

Answer 38

Population mean is the mean of a population, it is a parameter, sample mean is a mean of a sample, so it is a statistic. We use sample statistics to make inferences about population parameters.

Question 39

What is the median?

Answer 39

The middlest number

Question 40

What is the mode?

Answer 40

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

Question 41

When do we use mode?

Answer 41

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

Question 42

When we say “the average teenager” are we talking about the mean median or mode?

Answer 42

It depends, if we are talking height, it might be the mean, if we are talking about parental income, we’d probably use the median, if we are talking about music preference, we’d probably use the mode to talk about the average teenager.