Review Session 6 - École Polytechnique Fédérale de...

Post on 13-Jul-2020

1 views 0 download

Transcript of Review Session 6 - École Polytechnique Fédérale de...

ReviewSession 6

1

The residuals for the red estimation are …

21 2 3 4 5

33%

0%0%

33%33%

1.

2.

3. log log 4. Noneoftheabove5. Idon’t know

The residuals for the green estimation are …

31 2 3 4 5

0% 0%0%

100%

0%

1.

2.

3. log log 4. Noneoftheabove5. Idon’t know

If the error termsare not homoscedastic, itis better to …

41 2 3 4

29%

14%14%

43%

1. Useℓ minimization rather than ℓ2. Rescale tomake theerror term

homoscedastic3. Useℓ minimization rather than ℓ4. Idonotknow

We want to fit a data set  to a polynomial of degree 2:

.

Is this a linearregression model ? 

51 2 3

0%

13%

88%

1. Yes2. No3. Idon’t know

The green estimation corresponds to assuming that the errorterms (blue dot  green curve) are iidlognormal.

61 2 3 4

33%

22%

33%

11%

1. True2. Almost true3. False4. Idon’t know

Solution

7

The green estimation corresponds to assuming that the relative error terms(blue dot  green curve) are iid normal.

81 2 3 4

44%

0%

33%

22%

1. True2. Almost true3. False4. Idon’t know

Solution

9

The   matrix for the model

has full rank.

101 2 3 4 5

33%

11%11%

33%

11%

1. Yes2. No3. Itdependsonthe4. Itdependsonthe ′5. Idon’t know

We fit the model 

using least squares. 

The obtained line is such that the average distance from the points to the line is 0.

111 2 3 4

22%

0%

22%

56%

1. True2. False3. Itdepends onthedata4. Idon’t know

Solution

12

We fit the model 

using normminimization.

The obtained line leaves an equalnumber of points on each side

131 2 3 4

78%

0%0%

22%

1. True2. False3. Itdepends onthedata4. Idon’t know

Solution

14

Find the parameter for each of thesestandard Pareto PDFs

151 2 3 4 5

75%

0%0%0%

25%

1. 0.5; 1; 2; 32. 3; 2; 1; 0.53. 0.5; 2; 1; 34. 1; 2; 3; 0.55. Idon’t know

The skewnessindices S1, S2 and the Kurtosisindices K1, K2 are…

161 2 3 4 5 6 7 8 9

0% 0%

13% 13%

25%25%

0%

13%13%

1. S1>0,K1>0,S2>0,K2>02. S1<0,K1>0,S2>0,K2<03. S1>0,K1>0,S2=0,K2>04. S1<0,K1>0,S2=0,K2<05. S1>0,K1<0,S2>0,K2>06. S1<0,K1<0,S2>0,K2<07. S1>0,K1<0,S2=0,K2>08. S1>0,K1<0,S2=0,K2<09. Idon’t know