Test #1

Question 0

Variable

Answer 0

Any characteristic of a case

Question 1

Cases

Answer 1

The subjects of a data set (objects or people)

Question 2

Histogram

connected

Answer 2

Compares the values of different items, uses quantitative variables

Question 3

Bar chart
(not connected)

Answer 3

Compares the values of different items, uses categorical variables

Question 4

Ways to describe a bar chart/histogram

Answer 4

1. Shape
2. Center
3. Spread

Question 5

Outlier

Answer 5

Any value that falls outside the overall pattern, can affect mean and standard deviation

Question 6

Mode

Answer 6

The most common value in a data set, the major peaks of a bar chart/histogram

Question 7

Symmetric

Answer 7

Distribution creates a mirror image

Question 8

Skewed

Answer 8

Distribution is concentrated to the left or right

Question 9

Shape

Answer 9

Symmetric vs. skewed

Question 10

Center

Answer 10

Mean vs. median

Question 11

Spread

Answer 11

Standard deviation vs. IQR

Question 12

Categorical variables

Answer 12

Data is words, places cases into categories

Question 13

Quantitative variables

Answer 13

Data is numbers, measures the values of each case

Question 14

Median

Answer 14

The middle value or midpoint of a distribution

Question 15

Mean

Answer 15

The average value of a distribution

Question 16

Best ways to describe a distribution

Answer 16

Measure of center and measure of spread

Question 17

Q1

Answer 17

The median of the data which fall to the left of the overall median

Question 18

Q3

Answer 18

Median of the data which falls to the right of the overall median

Question 19

Five-number summary

Answer 19

Min
Q1
Median
Q3
Max

Question 20

Boxplot

Answer 20

A graph of the five-number summary

Question 21

IQR

Answer 21

Q3 - Q1 (the distance between the quartiles)

Question 22

Standard deviation formula

Answer 22

S = square root of: 1 / number of cases - 1 E (x1-mean)squared

Question 23

Standard deviation

Answer 23

How much distance there is from the mean, greater than 0.

Question 24

Normal distribution

Answer 24

Bell curve, symmetric, unimodal | N(mean, standard deviation)

Question 25

Unimodal

Answer 25

A distribution that contains one single peak

Question 26

68-95-99.7 rule

Answer 26

68% of observations fall within 1 standard deviation of the mean 95% fall within 2 SD of the mean 99.7% fall within 3 SD of the mean

Question 27

Z-score

Answer 27

Standardized value of x

Question 28

Z-score formula

Answer 28

z = x - mean / standard deviation

Question 29

Proportion

Answer 29

Decimals

Question 30

Response variable (y- axis)

Answer 30

Dependent variable, measures outcome

Question 31

Explanatory variable (x-axis)

Answer 31

Independent variable, explains or causes the change in the response variable

Question 32

Scatterplot

Answer 32

Shows the relationship between 2 quantitative variables measured on the same individuals

Question 33

Ways to describe a scatterplot

Answer 33

1. Form 2. Direction 3. Strength

Question 34

Form

Answer 34

Linear

Question 35

Direction

Answer 35

Positive vs. negative vs. none

Question 36

Strength

Answer 36

Strong vs. weak

Question 37

Correlation r formula

Answer 37

r = 1/n-1 (x-mean of x/standard deviation of x) (y-mean of y/standard deviation of y)

Question 38

Correlation r

Answer 38

Measures direction and strength. Between -1 and 1. Positive if positive correlation, negative if negative correlation

Question 39

Regression line

Answer 39

A straight line that shows how the response variable changes as the explanatory variable changes. Used to predict the value of y for a given value of x.

Question 40

Formula for predicting y (regression line)

Answer 40

y = slope (x) + intercept

Question 41

Slope formula

Answer 41

Slope = r (standard deviation of y / standard deviation of x)

Question 42

Slope

Answer 42

A change of one standard deviation in x corresponds to a change of r standard deviations in y

Question 43

Measure of center and spread for symmetric data

Answer 43

Mean and standard deviation

Question 44

Measure of center and spread for skewed data

Answer 44

Median and IQR