exam 2 (ch 6-8)

Question 1

two variables to have a distribution

Answer 1

bivariate data

Question 2

when scores on 2 variables are paired

Answer 2

bivariate data

Question 3

a quantitative relationship between two variables

Answer 3

correlation

Question 4

correlation does or does not mean causation?

Answer 4

not

Question 5

what kind of correlation is this: drunkness and motor skills?

Answer 5

negative correlation

Question 6

what kind of correlation is this: coffee intake and energy levels?

Answer 6

positive correlation

Question 7

what kind of correlation is this: hours on videos and length of toes

Answer 7

no correlation

Question 8

two fundamental techniques when it comes to stats

Answer 8

correlation and regression

Question 9

a stat that represents the strength and direction of a relationship between two variables

Answer 9

correlation coefficient

Question 10

correlation coefficient: the value of zero=

Answer 10

no relationship

Question 11

correlation coefiencent: value near -1 or 1 indicates

Answer 11

strong relationship

Question 12

correlation coefficient: values near zero but not zero

Answer 12

weak relationship

Question 13

use to illustrate a correlation

Answer 13

scatterplot

Question 14

the population of variance that two variable share

Answer 14

coefficient of determination

Question 15

coefficient of determination is also known as

Answer 15

shared variance or common variance

Question 16

a stat technique that allows you to make predictions

Answer 16

linear regression

Question 17

correlation is used to establish predictions or relationships?

Answer 17

relationship

Question 18

linear regression operates on what?

Answer 18

equation of a line (y=mx+b)

Question 19

distributions can be broadly categorized as what two things?

Answer 19

theoretical or empirical

Question 20

collecting data and plotting them on a frequency histogram

Answer 20

empirical distribution

Question 21

the distribution of scores from actual data

Answer 21

empirical distribution

Question 22

the distribution of scores one would expect to find

Answer 22

theoretical distribution

Question 23

hypothesized via math logic/ probability

Answer 23

theoretical distribution

Question 24

three types of theoretical distribution

Answer 24

normal, binomial, and rectangular distribution

Question 25

a measure of the likelihood that an event will occur

Answer 25

probability

Question 26

probability is at the heart of

Answer 26

theoretical distribution

Question 27

distribution in which all scores have the same frequency

Answer 27

rectangular distribution

Question 28

equal probability; all scores have the same probability of occurring

Answer 28

rectangular distribution

Question 29

distribution of the frequency of events that can have only two possible outcomes

Answer 29

binomial distribution

Question 30

bell-shaped theoretical distribution that predicts the frequency of occurrence of chance or random events

Answer 30

normal distribution

Question 31

standard deviation units are used to express measurements for what type of scores

Answer 31

z scores

Question 32

each trial is asymptotic which means

Answer 32

it never touches x axis; it goes on indefinitely

Question 33

A point that separates concave upward or concaves downward

Answer 33

inflection point

Question 34

a subset of a specified group

Answer 34

samples

Question 35

we use samples because

Answer 35

we do not have access to the population usually

Question 36

characteristics of a sample

Answer 36

stats

Question 37

entirely of a specified group

Answer 37

population

Question 38

characteristics of a population

Answer 38

parameter

Question 39

a subset of a population chosen so that each member (item/data point) has an equal probability of being selected

Answer 39

random sample

Question 40

best method of sampling

Answer 40

random sample

Question 41

a subset of the population chosen such that not all members (items.data points) have an equal chance of being selected

Answer 41

bias sample

Question 42

the degree to which your sample is reflective of the population you're interested in

Answer 42

representativeness

Question 43

representativeness can be achieved one of the two ways

Answer 43

via sampling technique and via large sample size

Question 44

based on all possible random samples drawn from the same population (using theory of probability)

Answer 44

same distribution

Question 45

the mean of sampling distribution

Answer 45

expected value

Question 46

standard deviation of a sampling distribution

Answer 46

standard error

Question 47

t/f: every sample of a sampling distribution of the mean is carefully selected from the same population size

Answer 47

false, it is random

Question 48

t/f: sample size is the same for all samples

Answer 48

true

Question 49

t/f: the number of samples is very small, less than 20

Answer 49

false

Question 50

t/f: the mean (x bar) is calculated for every sample

Answer 50

true

Question 51

the sample means (all the x bar) are arranged into what?

Answer 51

a frequency distribution

Question 52

as the sample size increases, the sample distribution looks more like the theoretical normal curve

Answer 52

central limit theorem

Question 53

the expected value (x bar of sampling distributions) is equal to

Answer 53

standard error

Question 54

t/f: the standard deviation of the sampling distribution is not equal to the standard deviation of the population

Answer 54

true

Question 55

if we dont have access to the parameters what can we use?

Answer 55

t distribution table

Question 56

any continuous probability distribution that arises when estimating the mean of a normally distributed population in situations where the sample size is small and/or the population standard deviation is unknown

Answer 56

t distribution

Question 57

determines the distribution that is most appropriate for your sample size

Answer 57

degrees of freedom

Question 58

you need three things to read a t -table

Answer 58

1. a degrees of freedom 2. determine if it's 1 or 2 tail 3. determine the alpha/confidence level

Question 59

the probability you are willing to be correct/incorrect about something

Answer 59

alpha level/confidence

Question 60

range of scores that are expected to contain a parameter (i.e. population mean)

Answer 60

confidence intervals