stats 8

Question 1

slope (m)=

Answer 1

rise/run

Question 2

Rise

Answer 2

The change in y for a given change in x

Question 3

Run

Answer 3

The change in x. It represents how much x increases or decreases,
which is typically by one unit when calculating the slope

Question 4

in statistics, a parameter is

Answer 4

the value of an unknown population
characteristic

Question 5

population regression line

Answer 5

the value of the dependent variable (y) is conditional on one or more independent variable

Question 6

the population regression line is interpreted as

Answer 6

the baseline or starting point of the dependent variable

Question 7

intercept

Answer 7

alpha

Question 8

slope

Answer 8

beta

Question 9

stochastic component

Question 10

sample regression model

Answer 10

if u know alpha and beta you can predict value of y

Question 11

parameter estimates

Question 12

systematic components

Answer 12

explains predictable relationship between ind and dep relationship

Question 13

OLS regression

Question 14

goodness-of-fit

Question 15

root mean-squared error (RMSE)

Question 16

model sum of squares

Question 17

confidence intervals

Question 18

t-ratio

Question 19

For OLS (Ordinary Least Squares) to produce unbiased and reliable estimates, a certain set of assumptions must be met

Answer 19

• normality of the error terms,
• no bias in the error term,
• homoscedasticity (constant variance of errors),
• no autocorrelation,
• X values are measured without errors,
• no omitted or unnecessary variables included in the model,
• parametric linearity,
• X must vary, and
• the sample size must exceed the number of parameters (variables) in the model (n > k).

Question 20

multiple regression model

Answer 20

we are able to control for another variable (Z) as we measure the relationship between our independent variable of interest and our dependent variable

Question 21

two variable regression model

Answer 21

a line is fit to a scatterplot of data

Question 22

the line in a two variable regression model is defined by its __ and serves as __

Answer 22

slope and y-intercept, a statistical model of reality

Question 23

how is two variables regression and three hypothesis-testing different

Answer 23

although they allow hypothesis testing, they don’t produce a statistical model

Question 24

the two elements (m and b) are described as the line’s

Answer 24

parameters

Question 25

in a two-variable regression, we represent y intercept by the greek letter _ and the slope parameter by greek letter _

Answer 25

a, B

Question 26

our theory about the underlying population in which we are interested is expressed in the

Answer 26

population regression models

Question 27

in the population regression models there is one additional components which does not correspond with what we are used to seeing in line formulae from math classes

Answer 27

this term is the stochastic or "random" component of our dependent variable

Question 28

why do we have the term stochastic

Answer 28

because we do not expect all of our data points to line up perfectly on a straight line

Question 29

in two variable regression we use information from the ___ to make inferences about the unseen population regression

Answer 29

sample regression model

Question 30

we place _ over the terms in the sample regression model that are estimates of terms from the unseen population regression model

Answer 30

hats

Question 31

our best guesses of the unseen population parameters a and b

Answer 31

parameter estimates

Question 32

another name for the estimated stochastic component

Answer 32

residual -meaning leftover

Question 33

another way to refer to u is to call it the

Answer 33

sample error term

Question 34

Which statistical test is appropriate for hypothesis testing when the independent variable is categorical and the dependent variable is also categorical -chi-square -correlational analysis -experimental analysis -T-test

Answer 34

-chi-square

Question 35

Which statistical test is appropriate for hypothesis testing when the independent variable is categorical and the dependent variable is numerical -T-test -chi-square test -correlational analysis -experimental analysis

Answer 35

-T-test

Question 36

In a study of whether support for environmental policies is related to ideology, which of the following could be the null hypothesis -There is no difference in support for environmental policies between liberals and conservatives -There is a significant relationship between ideology and support for environmental policies - Conservatives have a higher mean support for environmental policies than liberals - support for environmental policies is higher among liberals than among conservatives

Answer 36

-There is no difference in support for environmental policies between liberals and conservatives

Question 37

what does a standard error measure - the average