Flashcards in Chapter 1 Deck (54)

Loading flashcards...

1

## What are the two criteria for a random sample?

###
1. Equal chance of being selected

2. Independent of each other

2

## Explanatory variable

###
Independent variable

Predictor variable

Always on the x axis

3

## Response variable

### Dependent variable. What is being measured ? What do we want to predict ? Always on the y axis

4

## Frequency distribution

### Number of times each value of a variable occurs in a sample

5

## What is the criteria for a good sample?

###
Minimizing sampling error (precision )

Minimizing bias (accuracy)

6

## Explanatory variable

### Predictor variable

7

## What 4 things do you look for when interpreting histograms?

###
Over all pattern?

What is the shape?

What is the spread?

Any striking deviations?

8

## Graph to make with 2 categorical variables

### Grouped bar graph

9

## Graph to make with one categorical and one numerical variable

### Bar graph

10

## What does standard deviation measure ?

### Measure of how different values are from the mean

11

## How is standard deviation calculated ?

### The square root of variance

12

## What is coefficient of variation ?

### Expresses the standard deviation as a percentage of the mean

13

## What happens when the coefficient of variation increases ?

### There is more variability

14

## What is IQR ? How is it calculated ?

### Inter quartile range = difference between the first and third quartile.

15

## Which measurement methods are more sensitive to extremes?

### Standard deviation and mean !

16

## What three things describe the shape of a distribution ?

###
Symmetric or asymmetric ?

Center of data ?

Spread of data ?

17

## What spread measurement is associated with median?

### Inter quartile range

18

## How do outliers affect mean? Median?

###
Mean increases

Median remains unchanged !

19

## How does the mean relate to the median if the data is left skewed ?

### Mean is larger than the median

20

## How are mean and median related when the spread is symmetrical ?

### Mean = median

21

## What measure of location should be used if the distribution is symmetrical ?

###
Mean

22

## What part of the box plot represents the IQR ?

### The entire box

23

## What will a box plot look like if it is left skewed ?

### Median line is closer to the top of the box

24

## What will a box plot look like if it is right skewed ?

### The median line is closer to the bottom of the box

25

## Explanatory variable

### Predictor variable

26

## What 4 things do you look for when interpreting histograms?

###
Over all pattern?

What is the shape?

What is the spread?

Any striking deviations?

27

## Graph to make with 2 categorical variables

### Grouped bar graph

28

## Graph to make with one categorical and one numerical variable

### Bar graph

29

## What does standard deviation measure ?

### Measure of how different values are from the mean

30