Chapter 12

Question 1

welke variabele op y as

Answer 1

y = reponse

Question 2

welke variable op x as

Answer 2

x = explanatory

Question 3

correlation falls between

Answer 3

-1 and 1

Question 4

the stronger the linear correlation, (r)

Answer 4

the larger r is

Question 5

where does the value of r NOT depend on

Answer 5

• the variables’ unit
• which one is the response and the explanatory variable

Question 6

when is a value an outlier

Answer 6

• way higher or lower than other variables
• does not fall into the straight line of the regression

Question 7

a subject who is average on x is predicted
to be average on y

Answer 7

oke

Question 8

least squares line

Answer 8

de regressielijn, want sum of squares is het kleinste

Question 9

The probability distribution of y values at a fixed value of x is a

Answer 9

conditional distribution

Question 10

A regression model describes how the population mean my of each conditional distribution for the response variable depends on the value x of the explanatory variable. A straight-line regression model uses the line my = a + bx to connect the means. The model also has a parameter s that describes variability of observations around the mean of y at each x value.

Answer 10

oke

Question 11

assumptions linear regression

Answer 11

• linear
• normal
• randomized

Question 12

two sided significance test about population slope B

Answer 12

H0: b = 0, Ha: b =/= 0
test statistic: t = b-0/se
2* t.dist with df= n-2

Question 13

95% CI for slope estimate

Answer 13

b +- t.0251*se
df = n-2

Question 14

two sided test….

Answer 14

helft van p!!

Question 15

interpret what the confidence interval implies…

Answer 15

On average, the response variable increases between (CI, CI) for every unit of the explanatory variable.