significance and regression coeffeicent

Question 1

what tests would you use for significance and regression coeffeincent

Answer 1

• F test
• likelhood ratio test
• wald test

Question 2

what has wider limits

Answer 2

prediction limits (unaffected by sample size)

Question 3

what has narrower limits

Answer 3

confiednce intervals (affected by the sample size)

Question 4

what is the general form for linear regression

Answer 4

predict y for a given value of x

Question 5

what is the simple linear regressiobn model

Answer 5

y=a+bx+e

Question 6

what is ‘a’ within a line with equation y= a +bx

Answer 6

= intercept or constant

Question 7

what is ‘b’ within a line with equation y= a +bx

Answer 7

slope

Question 8

what is the aim of regression anyalsis

Answer 8

find the line for the data in hand

Question 9

what is residual

Answer 9

(random error)
it is teh difference between each obsereved data points

Question 10

what is homosedasity

Answer 10

constant variance

Question 11

what is there at each fixed value of x

Answer 11

a distint distribution of y that have differnet means but the same shape

Question 12

what is a regression line

Answer 12

best fit straight line taht joins the values of y

Question 13

what is the best way to look at normality

Answer 13

histograms and/or normal probabilty plots

Question 14

what is the best way to look at linerailty

Answer 14

scatterplot

Question 15

what is the main advantage of regression framework

Answer 15

capabilty of fitting multiple predictors

Question 16

what does it mean if r=0

Answer 16

there is no linear relatiojnship between the variables

Question 17

what does r>0 mean

Answer 17

positive slope

Question 18

what does r<0 mean

Answer 18

negative slope

Question 19

out of correlation and regression which one provides more infromative

Answer 19

regression

Question 20

what happens to the confidence interval as the sample size increases

Answer 20

gets narrower

Question 21

what happens to the prediction intervals when the population size increases

Answer 21

it is unaffected

Question 22

what typoe of varaible is y

Answer 22

dependant vairble

Question 23

what type of variavble is x

Answer 23

independant varibale

Question 24

what is a residual

Answer 24

the difference between each obserevd data and is predicted by the fitted line
they are assumed to be normal

Question 26

what is pearson r applicable to

Answer 26

continous varibales

Question 27

what are the values for r between

Answer 27

-1 and +1

Question 28

what is teh r value for a positive slope

Answer 28

if biggeer than 0 = positive

Question 29

what is teh r value for a negative slope

Answer 29

if less than 0 then negative

Question 30

what does it mean when r =0

Answer 30

no linear relation between the variblaes

Question 31

what does the p value depend on

Answer 31

r and sample size

Question 32

what are the disadvantages of correlation

Answer 32

only extreme values are easily interpreatble

Question 33

what test would you use for agreement

Answer 33

bland altman

Question 34

what is good agreement in bland altman

Answer 34

small bias, narrow limits of agreement and most data falloing within the limits

Question 35

what is the limit of agreement in bland altman

Answer 35

biaas +or - 1.96X sd