MATH 4387 HW2
Yunzhou Li
1:
y f ( y ) dy
E(Y ) =
y ey dy
=
0
0
2
E( Y
=
y
1
=
2
f ( y ) dy
=
0
V(Y) = E( Y 2 
y 2 ey dy
=
2
2
1
2
0
E(Y )2 =

1
2
=
2
2
2:
1
4
+2 =
+2
1
16
V(4Y+2) = V(4Y) = 16V(Y) =16 2 =
2
E(4Y+2) = 4E(Y)+2 = 4
3:
1
f x = 6 ( 1 y
MATH 4387
Yunzhou Li
HW3
2.1
he dataset teengamb concerns a study of teenage gambling in Britain. Fit a regression model with
the expenditure on gambling as the response and the sex, status, income and verbal score as
predictors. Present the output.
(a) W
MATH4387 HW5
Yunzhou Li
3. Using the teengamb data, fit a model with gamble as the response and the other variables as
predictors.
(a) Which variables are statistically significant at the 5% level?
sex and income are statistically significant at the 5% l
MATH 4387
HW4
Yunzhou Li
1.Consider a simple linear regression of log(fertility) on pctUrban using the UN11 data set in the
alr4 package.
a.
Write the model you are fitting (in terms of the mean of log(fertility conditional on
knowing the value of pctUrba