First exam based on chapters 1-5

Question 1

Two meanings of statistics

Answer 1

formal & informal

Question 2

Formal Statistics

Answer 2

a branch of math that focuses on organizing, summarizing, analyzing and interpreting data in a table or graph or numerically

Question 3

Informal Statistics

Answer 3

numbers representing something

Question 4

What do we use to analyze and interpret data?

Answer 4

Inferential stats

Question 5

inference stats

Answer 5

make a inference or draw a conclusion from a sample from a population

Question 6

Data

Answer 6

the info we gather from people, places and things

Question 7

two types of formal stats

Answer 7

descriptive & inferential

Question 8

descriptive stats

Answer 8

organize & summarize data

Question 9

inferential stats

Answer 9

analyze & interpret data

Question 10

variable

Answer 10

a characteristic that can assume different variables ex:height

Question 11

value

Answer 11

a possible number or category a score can assume, these belong to a variable

Question 12

score

Answer 12

the value of a variable for a specific person, place or thing

Question 13

two types of variables

Answer 13

numeric & nominal

Question 14

numeric variables (quantitative variable)

Answer 14

variables whose values are numbers, includes ordinal & interval

Question 15

(equal) interval variables

Answer 15

the distance and difference between two sequential values is the same

Question 16

ordinal variable

Answer 16

categorical variable includes categories divided into groups and are relatively ranked, ex: class rank

Question 17

ratio variable

Answer 17

has an absolute zero

Question 18

What is the one benefit of frequency tables?

Answer 18

they provide an organized overview of how often values occur in a group of scores

Question 19

How do you calculate the percentage on a frequency table?

Answer 19

You divide the frequency by the total number of scores, N=30 and the frequency is 1 the perfect is 3.3%

Question 20

where do the values and frequencies go on the frequency graph ?

Answer 20

the values go on the x-axis & the frequencies go on the y-axis

Question 21

Frequency distributions

Answer 21

the shape of a frequency graph reflects the distribution of scores across values of a variable, characterize the pattern of data

Question 22

unimodal

Answer 22

one highest point in the graph, this is the most frequent
(ex: scores on an IQ test)

Question 23

bimodal

Answer 23

two equally high points on a distribution (ex: age of people at a park)

Question 24

rectangular distribution

Answer 24

all values of the same frequency (ex: number of children in each grade)

Question 25

roughly symmetrical

Answer 25

one side of the face is the same as the other, a mirror image of the other

Question 26

positively skewed

Answer 26

skewed to the left side

Question 27

negatively skewed

Answer 27

skewed on the right side

Question 28

mean

Answer 28

average of the scores, add up all the scores and divide them by N

Question 29

Σ

Answer 29

sigma

Question 30

N

Answer 30

number of scores in our group of scores

Question 31

With means, averages should never be applied to ?

Answer 31

individuals, they are only calculated from individuals

Question 32

mode

Answer 32

most common value, it is the central tendency for nominal variables

Question 33

median

Answer 33

middle score, when arranged from lowest to highest

Question 34

variance table

Answer 34

4 columns, X, M, X-M, X-M^2

Question 35

X

Answer 35

score to the people in particular the raw score

Question 36

variance steps

Answer 36

1. subtract the mean from each score 2. square each of these deviation scores 3. sum the squared deviation scores 4. divide the sum of squared deviations by N

Question 37

standard deviation steps

Answer 37

1. calculate the variance (SD^2) 2. take the square root of the variance

Question 38

X is a

Answer 38

raw score

Question 39

Z is a

Answer 39

standardized score that talks in Standard deviation units, they are comparable and combinable

Question 40

Z score formula

Answer 40

Z=X-M/SD

Question 41

X-M is a deviation score what does that tell us?

Answer 41

It tells us how far away the X is away from the mean (M)

Question 42

What is the goal of the z-score?

Answer 42

to convert the raw score to standard deviation units

Question 43

What happens if the z-score is negative or positive?

Answer 43

Positive- the raw score is above the mean Negative-the raw score is below the mean

Question 44

How are sample stats represented?

Answer 44

with roman letters like M, SD, SD2 Sample statistics can change from sample to sample because they are subsets of the population, each sample would be different

Question 45

How are population parameters represented?

Answer 45

Greek letters mu (μ) -mean σ-standard deviation these are fixed quantities

Question 46

conceptual interpretation

Answer 46

tells us the number of standard deviation units the raw score is above or below the mean

Question 47

How do you calculate a z score back to a raw score?

Answer 47

X= ZxSD + M

Question 48

substantive interpretation

Answer 48

applies it’s meaning to the specific scenario

Question 49

NHST (Null hypothesis significance testing) Step 1

Answer 49

Restate your research question into hypotheses about population, Null hypothesis H(0) Research hypothesis H(1)

Question 50

Null hypothesis

Answer 50

population 1 = population 2 meaning there is no difference

Question 51

Research hypothesis

Answer 51

population 1 mean is greater than (>) population 2 mean

Question 52

Population 2 in research hypotheses is?

Answer 52

people in general

Question 53

Step 2 of NHST

Answer 53

determine characteristics of the comparison distribution under the null hypothesis

Question 54

What do we do if our sample z-score exceeds the critical cutoff z-scores

Answer 54

we reject the null hypothesis