DECK 2: UNIT 1 part A

Question 1

When drawing a graph or chart, what do you have to remember to do?

Answer 1

LABEL AXES, make a KEY(if needed ) AND GIVE IT A NAME!!! “Figure 1: Age and Food Preference”

Question 2

When are box plots used most often?

Answer 2

When comparing a bunch of different sets of data.

Question 3

What is the IQR?

Answer 3

Interquartile range… a measure of spread. Q3-Q1. The distance from Q1 to Q3. The regular range is Hi-Lo, this is the inner range, the interquartile range.

Question 4

How can you match boxplots to histograms?

Answer 4

USE THE FISH TANK METHOD!

Question 5

What is a CUMULATIVE FREQUENCY GRAPH?

Answer 5

An OGIVE. It shows the added up totals as you go left to right.

Question 6

What do OGIVES look like?

Answer 6

They all start at the bottom left (0%) and go to top right (100%)

Question 7

What is a “percentile?”

Answer 7

It tells you the percent of data BELOW a certain value

Question 8

How do you find a certain percentile on an OGIVE?

Answer 8

Start at the % on the Y axis.. travel horizontally to the right until you hit the line, then straight down to the X axis. That data value is the percentile.

Question 9

How can you turn OGIVES into histograms?

Answer 9

RECTANGLE DROP! (bin drop)

Question 10

where are the “outlier fences?”

Answer 10

1.5 IQR above Q3 and 1.5 IQR below Q1. Just a rule of thumb.

Question 11

What is the five number summary?

Answer 11

min, Q1 , Q2(median), Q3 and max

Question 12

How do you find Q1 and Q3?

Answer 12

Q1 is the median of the bottom half and Q3 is the median of the upper half (they are the 25th and 75th percentiles)

Question 13

What percentile is Q3?

Answer 13

75th

Question 14

How do you describe distributions (histograms)?

Answer 14

Shape-Cener-Spread- and STRANGE (Outliers and gaps) some say GSOCS. where’s yo GSOCS?

Question 15

How can you describe spread?

Answer 15

range, IQR, stand dev, variance, or simply say: From here, to about here

Question 16

How can you describe shape?

Answer 16

TWO THINGS: modes and symmetry.

unimodal, bimodal, multimodal AND uniform, symmetric, skewed

Question 17

How do you describe CENTER for bimodal or multimodal?

Answer 17

talk about the modes (the lumps, the clusters)

Question 18

How do you describe CENTER for skewed or distributions with outliers?

Answer 18

use the MEDIAN

Question 19

How do you describe CENTER for unimodal and symetric distributions?

Answer 19

use the MEAN

Question 20

How do you descrive SPREAD for unimodal and symmetric distributions?

Answer 20

use the standard deviation

Question 21

How do you describe SPREAD for skewed distributions (or distributions with outliers?)

Answer 21

Use the IQR

Question 22

How do you describe SPREAD for bimodal or multimodal?

Answer 22

talk about the outer edges of the clusters “from here to here” or use the IQR.

Question 23

If asked to compare distributions, what should you write about?

Answer 23

A sentence comparing the SHAPES. A sentence comparing the CENTERS. A sentence comparing the SPREADS. and a sentence comparing the STRANGE STUFF. (GSOCS)

Question 24

What does GSOCS stand for?

Answer 24

Gaps Shape Outliers Center Spread (put on your gsocs when comparing distributions) be sure to talk about each one clearly (make a list)

Question 25

How can you describe the center of a distribution?

Answer 25

OPTIONS: give the mean (balance), median (splits area in half), mode (peaks, if bimodal talk about both modes) or say “centered around ____”

Question 26

How can you tell if variables in a contingency table are independent?

Answer 26

If the distributions are the same across the variables.. Then it doesn’t DEPEND… so INDEPENDENT. Ex: 30% of freshman and 30% of seniors like cabbage.

Question 27

What do you call things that are not independent?

Answer 27

associated. Or not independent. We generally don’t say DEPENDENT (unless talking about y variable on a scatterplot).

Question 28

Give an example of independent variables

Answer 28

If 80% prefer cheese and only 20% prefer pepperoni IN EACH GRADE AT BHS…then they all have the same preference, so grade doesn’t matter. We say “school year and pizza choice are independent”

Question 29

marginal distribution

Answer 29

distribution in the margins (outside of the table). The overall distributions of a single variable in contingency table.

Question 30

Gender and Video Game playing are___________ because_______

Answer 30

associated (or not independent) because a higher percentage of males play video games. (think.. It depends on gender)

Question 31

Year in school (F,S,J,S) and Pizza Preference (pepperoni or cheese) are __________ because _______________

Answer 31

independent because all grades have similar preference distributions..
40% cheese, 30%pepperoni, 20% veggie 10% other

Question 32

What is a contingency table?

Answer 32

shows distributions across 2 variables like gender and music pref. AKA 2-way table

Question 33

Association and Independence. How are they related?

Answer 33

Variables are either independent or associated. Meaning: if one impacts the other then we say there is an association. If not, Then they are independent.

Question 34

When there is a relationship between two variables, we say that they are

Answer 34

associated (or not independent)

Question 35

When there is no relationship between two variables, we say they are

Answer 35

independent (or not associated)

Question 36

independent is the same as __________

Answer 36

not associated

Question 37

associated is the same as __________

Answer 37

not independent

Question 38

not associated is the same as being ____________

Answer 38

independent

Question 39

Give a quick example of associated variables

Answer 39

A higher percentage of boys play video games than girls so we say “gender and video game playing are associated” or “gender and video game playing are not independent”

Question 40

<p>what is a conditional distribution?</p>

Answer 40

<p>A distribution with a condition (within the table), along only one row or one column… NOT IN THE MARGINS. You are given a condition.. Then read along that row or column.</p>

Question 41

not independent is the same as

Answer 41

associated

Question 42

What percent of the data is above Q3?

Answer 42

25%

Question 43

What percent of the data is between Q1 and Q3?

Answer 43

the middle 50%. That is the IQR

Question 44

What is Q2 also known as?

Answer 44

the median

Question 45

What percent of the data is below Q2?

Answer 45

50%