Lösungen / Statistik 2/08
Remove @ "Global`∗" D
1.
ü a
f @ x_, y_ D := 1 ê H 2 Pi L E ^ H−1 ê 2 H x ^ 2 + y ^ 2 LL ; Plot3D @ f @ x, y D , 8 x, −3, 3 < , 8 y, −3, 3 <D ;
-2
0
2
-2 0
2 0
0.05 0.1 0.15
-2
0
2
μX = 3; μY = 2; σX = 3; σY = 2 ê 3; ∑XY = 1 ê 2;
f1 @ x_, y_ D := 1 ê H 2 Pi σX σY Sqrt @ 1 − ∑XY ^ 2 DL E ^ HH −1 ê H 2 H 1 − ∑XY ^ 2 LL
HHH x − μX L ^ 2 L ê H σX ^ 2 L + HH y − μY L ^ 2 L ê H σY ^ 2 L − 2 ∑XY H x − μX L H y − μY L ê H σX σY LLLL ;
? f1 Global`f1
f1 @ x_, y_ D : =
− Hx−μXL2
σX2 +Hy−μYL2
σY2 −2∑XYHx−μXL Hy−μYL σXσY 2H1−∑XY2L 2π σXσYè!!!!!!!!!!!!!!!!!1−∑XY2
Plot3D @ f1 @ x, y D , 8 x, −2, 8 < , 8 y, −2, 8 < , PlotRange → 8 0, 0.1 <D ;
-2 0
2 4
6
8 -2 0
2 4
6 8
0 0.02 0.04 0.06 0.08 0.1
-2 0
2 4
6
ü b
Integrate @ Integrate @ f @ x, y D , 8 x, −a, a <D , 8 y, −a, a <D Erf A a
è!!! 2 E
2Integrate @ Integrate @ f @ x, y D , 8 x, −Infinity, Infinity <D , 8 y, −Infinity, Infinity <D 1
Integrate @ Integrate @ f @ x, y D , 8 x, −a, a <D , 8 y, −a, a <D ê . 8 a → Infinity <
1
Integrate @ Integrate @ f @ x, y D , 8 x, −Infinity, Infinity <D , 8 y, −Infinity, Infinity <D 1
Integrate @ Integrate @ f1 @ x, y D , 8 x, −Infinity, Infinity <D , 8 y, −Infinity, Infinity <D 1
Integrate @ f1 @ x, y D , 8 x, −Infinity, Infinity <D 3
−98 H−2+yL22 è!!!!!!! 2 π
Integrate @ f1 @ x, y D , 8 y, −Infinity, Infinity <D
−181 H−3+xL2
3 è!!!!!!! 2 π
ü c
F @ x_, y_ D := Integrate @ Integrate @ f @ u, v D , 8 u, −Infinity, x <D , 8 v, −Infinity, y <D
F @ 0, 0 D 1 4
F @ 0, Infinity D 1
2
F @ Infinity, 0 D 1
2
F @ Infinity, Infinity D 1
F1 @ x_, y_ D := Integrate @ Integrate @ f1 @ u, v D , 8 u, −Infinity, x <D , 8 v, −Infinity, y <D NF1 @ x_, y_ D := NIntegrate @ Integrate @ f1 @ u, v D , 8 u, −Infinity, x <D , 8 v, −Infinity, y <D NF1 @ 3, 2 D
0.333333
2.
ü a
Xbar=X1+X2;
m=m1=m2;
s^2=s1^2 / 2 = s2^2 / 2;
ü b
Remove @ f2, F2 D
f2 @ x_, σ_, μ_ D := 1 ê H Sqrt @ 2 Pi D σ L E ^ H −1 ê H 2 L HH x − μ L ^ 2 ê σ^ 2 LL ; F2 @ x_, σ_, μ_ D := Integrate @ f2 @ u, σ, μ D , 8 u, −Infinity, x <D F2 @ Infinity, σ, μD êê Simplify
è!!!!!!! 2 1 π σ If A Re @σ
2D > 0, è!!!!!!! 2 π è!!!!!! σ
2, Integrate A
−Hu−μL2σ22, 8 u, −∞, ∞< , Assumptions → Re @σ
2D ≤ 0 EE
F2 @ Infinity, 4, 5 D 1
F2 @μD
F2 @μD
f3 @ x_, σ_, μ_ D := 1 ê H Sqrt @ 2 Pi D c1 σL E ^ H−1 ê H 2 L HH c1 x + c2 − H c1 μ + c2 LL ^ 2 ê H c1 σL ^ 2 LL ; F3 @ x_, σ_, μ_ D := Integrate @ f3 @ u, σ, μD ∗ Evaluate @ D @ c1 u + c2, u DD , 8 u, −Infinity, x <D F3 @ Infinity, 4, 5 D
1
3.
ü a
k @ n_ D := 1 ê H 2 ^ H n ê 2 L Gamma @ n ê 2 DL Table @ k @ n D , 8 n, 0, 10 <D
9 0, 1 è!!!!!!! 2 π , 1
2 , 1 è!!!!!!! 2 π , 1
4 , 1
3 è!!!!!!! 2 π , 1
16 , 1
15 è!!!!!!! 2 π , 1
96 , 1
105 è!!!!!!! 2 π , 1 768 = f4 @ x_, n_ D := k @ n D x ^ HH n − 2 L ê 2 L E ^ H−x ê 2 L
Plot @8 f4 @ x, 10 D , f4 @ x, 5 D< , 8 x, 0, 10 <D ;
2 4 6 8 10
0.025 0.05 0.075 0.1 0.125 0.15
F4 @ x_, n_ D := Integrate @ f4 @ u, n D , 8 u, 0, x <D F4 @ 2, 5 D
− 10
3 è!!! π + Erf @ 1 D F4 @ 2, 5 D êê N 0.150855
ü b
Remove @ f5, f6, F5, F6 D
f5 @ z_, n_ D := Gamma @H n + 1 L ê 2 D ê Sqrt @ n Pi D ê Gamma @ n ê 2 D ê H 1 + z ^ 2 ê n L ^ HH n + 1 L ê 2 L
Plot @8 f5 @ x, 10 D< , 8 x, −10, 10 <D ;
-10 -5 5 10
0.1 0.2 0.3
F6 @ z_, a_, n_ D := Integrate @ f5 @ u, n D , 8 u, a, z <D
? F6 Global`F6
F6 @ z_, a_, n_ D : = Ÿ
az
f5 @ u, n D u
F6 @ z, a, n D i
k jjjjjjH −a + z L Gamma A 1 + n 2 E If Ai
k jjj Im A è!!! n
a − z E + Re A a
a − z E ≥ 1 »» Im A è!!! n
−a + z E + Re A a
−a + z E ≥ 0 »» Im A a − è!!! n a − z E ≠ 0 y
{ zzz &&
i
k jjj Im A è!!! n
−a + z E + Re A a
a − z E ≥ 1 »» Im A è!!! n
−a + z E Re A a
−a + z E »» Im A è!!! n
a − z E ≥ Re A a a − z E »»
Im A a + è!!! n a − z E ≠ 0 y
{ zzz , 1
a − z J a Hypergeometric2F1 A 1
2 , 1 + n 2 , 3
2 , − a
2n E − z Hypergeometric2F1 A 1
2 , 1 + n 2 , 3
2 , − z
2n EN , Integrate Ai
k jjj n + H a + u H−a + z LL
2n
y { zzz
1 2 H−1−nL
, 8 u, 0, 1 < , Assumptions →
! i
k jjji k jjj Im A è!!! n
a − z E + Re A a
a − z E ≥ 1 »» Im A è!!! n
−a + z E + Re A a
−a + z E ≥ 0 »» Im A a − è!!! n a − z E ≠ 0 y
{ zzz &&
i
k jjj Im A è!!! n
−a + z E + Re A a
a − z E ≥ 1 »» Im A è!!! n
−a + z E Re A a
−a + z E »»
Im A è!!! n
a − z E ≥ Re A a
a − z E »» Im A a + è!!! n a − z E ≠ 0 y
{ zzzy { zzzEE y
{ zzzzzz ì Iè!!! n è!!! π Gamma A n 2 EM F6 @ 4, a, 6 D
H 4 − a L I −1127 è!!!!!! 22 +
2662 aHH135+30 a6+a2L5ê22+2 a4LM 10648 H−4 + a L
Limit @ Evaluate @ F6 @ 4, a, 6 DD , a → −Infinity D 1
2 + 1127 484 è!!!!!! 22 N @ % D
0.996441
Limit @ Evaluate @ F6 @ 1, a, 6 DD , a → −Infinity D êê N 0.822041
Limit @ Evaluate @ F6 @ 0, a, 6 DD , a → −Infinity D êê N 0.5
Limit @ Evaluate @ F6 @−4, a, 6 DD , a → −Infinity D êê N 0.00355949
Limit @ Evaluate @ F6 @ 20, a, 6 DD , a → −Infinity D êê N 0.999999
Plot @8 F6 @ x, −1000, 10 D< , 8 x, −10, 10 <D ;
-10 -5 5 10
0.2 0.4 0.6 0.8 1
Plot @8 F6 @ x, −10 ^ 10, 10 D< , 8 x, −10, 10 <D ;
-10 -5 5 10
0.005 0.01 0.015 0.02
ü c
F6 @ 2, a, 5 D i
k jjjH 2 − a L i
k jjj −370 + 405 a H 25 + 3 a
2L
H 5 + a
2L
2− 243 è!!! 5 ArcTan A 2
è!!! 5 E + 243 è!!! 5 ArcTan A a è!!! 5 Ey
{ zzzy { zzz ì I 243 è!!! 5 H −2 + a L π M
Limit @ F6 @ 2, a, 5 D , a → −Infinity D 1 +
74è!!!!5
243
+ ArcTan A
è!!!!25E
N @ % D 0.94903
4
Remove @ "Global`∗" D
f @ z_, n_ D := Gamma @H n + 1 L ê 2 D ê H Sqrt @ n Pi D Gamma @ n ê 2 DL ∗ 1 ê H 1 + z ^ 2 ê n L ^ HH n + 1 L ê 2 L ; f @ z, n D
I 1 +
zn2M
12 H−1−nLGamma @
1+n2D è!!! n è!!! π Gamma @
n2D
F @ z_, a_, n_ D := Gamma @H n + 1 L ê 2 D ê H Sqrt @ n Pi D Gamma @ n ê 2 DL Integrate @ 1 ê H 1 + u ^ 2 ê n L ^ H n + 1 L , 8 u, a, z <D ; F @ z, a, n D i
k jjjjH −a + z L Gamma A 1 + n 2 E If Ai
k jjj Im A è!!! n
a − z E + Re A a
a − z E ≥ 1 »» Im A è!!! n
−a + z E + Re A a
−a + z E ≥ 0 »» Im A a − è!!! n a − z E ≠ 0 y
{ zzz &&
i
k jjj Im A è!!! n
−a + z E + Re A a
a − z E ≥ 1 »» Im A è!!! n
−a + z E Re A a
−a + z E »»
Im A è!!! n
a − z E ≥ Re A a
a − z E »» Im A a + è!!! n a − z E ≠ 0 y
{ zzz , 1 a − z J a Hypergeometric2F1 A 1
2 , 1 + n, 3 2 , − a
2n E − z Hypergeometric2F1 A 1
2 , 1 + n, 3 2 , − z
2n EN , Integrate Ai
k jjj n + H a + u H−a + z LL
2n
y {
zzz
−1−n, 8 u, 0, 1 < , Assumptions →
! i k jjji
k jjj Im A è!!! n
a − z E + Re A a
a − z E ≥ 1 »» Im A è!!! n
−a + z E + Re A a
−a + z E ≥ 0 »» Im A a − è!!! n a − z E ≠ 0 y
{ zzz &&
i
k jjj Im A è!!! n
−a + z E + Re A a
a − z E ≥ 1 »» Im A è!!! n
−a + z E Re A a
−a + z E »»
Im A è!!! n
a − z E ≥ Re A a
a − z E »» Im A a + è!!! n a − z E ≠ 0 y
{ zzzy { zzzEEy
{ zzzz ì Iè!!! n è!!! π Gamma A n 2 EM F @ z, −Infinity, n D
i k jjjjj
jj Gamma A 1 + n 2 E
If A Re @ n D > − 1 2 ,
"#####
1n
è!!! π Gamma @
12+ n D
2 Gamma @ n D + z Hypergeometric2F1 A 1
2 , 1 + n, 3 2 , − z
2n E , Integrate AJ n + u
2n N
−1−n, 8 u, −∞, z < , Assumptions → Re @ n D ≤ − 1 2 EE y
{ zzzzz
zz ì I è!!! n è!!! π Gamma A n
2 EM
ü a
f @ z, 10 D 63 "#####
52