problem 10

Problem 2

Describe the null hypotheses to which the p-values given in Table 3.4 correspond. Explain what conclusions you can draw based on these p-values. Your explanation should be phrased in terms of sales, TV, radio, and newspaper, rather than in terms of the coefficients of the linear model.

The null hypotheses associated with table 3.4 are that advertising budgets of “TV”, “radio” or “newspaper” do not have an effect on sales. More precisely H(1)0:β1=0, H(2)0:β2=0 and H(3)0:β3=0. The corresponding p-values are highly significant for “TV” and “radio” and not significant for “newspaper”; so we reject H(1)0 and H(2)0 and we do not reject H(3)0. We may conclude that newspaper advertising budget do not affect sales

Problem 9

This question involves the use of multiple linear regression on the Auto data set.

library(ISLR2)
attach(Auto)

(a) Produce a scatterplot matrix which includes all of the variables in the data set.

pairs(Auto)

(b) Compute the matrix of correlations between the variables using the DataFrame.corr() method.

names(Auto)
[1] "mpg"          "cylinders"    "displacement" "horsepower"   "weight"      
[6] "acceleration" "year"         "origin"       "name"        
cor(Auto[1:8])
                    mpg  cylinders displacement horsepower     weight
mpg           1.0000000 -0.7776175   -0.8051269 -0.7784268 -0.8322442
cylinders    -0.7776175  1.0000000    0.9508233  0.8429834  0.8975273
displacement -0.8051269  0.9508233    1.0000000  0.8972570  0.9329944
horsepower   -0.7784268  0.8429834    0.8972570  1.0000000  0.8645377
weight       -0.8322442  0.8975273    0.9329944  0.8645377  1.0000000
acceleration  0.4233285 -0.5046834   -0.5438005 -0.6891955 -0.4168392
year          0.5805410 -0.3456474   -0.3698552 -0.4163615 -0.3091199
origin        0.5652088 -0.5689316   -0.6145351 -0.4551715 -0.5850054
             acceleration       year     origin
mpg             0.4233285  0.5805410  0.5652088
cylinders      -0.5046834 -0.3456474 -0.5689316
displacement   -0.5438005 -0.3698552 -0.6145351
horsepower     -0.6891955 -0.4163615 -0.4551715
weight         -0.4168392 -0.3091199 -0.5850054
acceleration    1.0000000  0.2903161  0.2127458
year            0.2903161  1.0000000  0.1815277
origin          0.2127458  0.1815277  1.0000000

(c) Use the sm.OLS() function to perform a multiple linear regression with mpg as the response and all other variables except name as the predictors. Use the summarize() function to print the results. Comment on the output. For instance:

  i. Is there a relationship between the predictors and the response?
fit2 <- lm(mpg ~ . - name, data = Auto)
summary(fit2)

Call:
lm(formula = mpg ~ . - name, data = Auto)

Residuals:
    Min      1Q  Median      3Q     Max 
-9.5903 -2.1565 -0.1169  1.8690 13.0604 

Coefficients:
               Estimate Std. Error t value Pr(>|t|)    
(Intercept)  -17.218435   4.644294  -3.707  0.00024 ***
cylinders     -0.493376   0.323282  -1.526  0.12780    
displacement   0.019896   0.007515   2.647  0.00844 ** 
horsepower    -0.016951   0.013787  -1.230  0.21963    
weight        -0.006474   0.000652  -9.929  < 2e-16 ***
acceleration   0.080576   0.098845   0.815  0.41548    
year           0.750773   0.050973  14.729  < 2e-16 ***
origin         1.426141   0.278136   5.127 4.67e-07 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 3.328 on 384 degrees of freedom
Multiple R-squared:  0.8215,    Adjusted R-squared:  0.8182 
F-statistic: 252.4 on 7 and 384 DF,  p-value: < 2.2e-16

We can answer this question by again testing the hypothesis H0:βi=0 ∀i. The p-value corresponding to the F-statistic is 2.037105910^{-139}, this indicates a clear evidence of a relationship between “mpg” and the other predictors.

ii. Which predictors appear to have a statistically significant relationship to the response?

We can answer this question by checking the p-values associated with each predictor’s t-statistic. We may conclude that all predictors are statistically significant except “cylinders”, “horsepower” and “acceleration”.

iii. What does the coefficient for the year variable suggest?

The coefficient ot the “year” variable suggests that the average effect of an increase of 1 year is an increase of 0.7507727 in “mpg” (all other predictors remaining constant). In other words, cars become more fuel efficient every year by almost 1 mpg / year.

(d) Produce some of diagnostic plots of the linear regression fit as described in the lab. Comment on any problems you see with the fit. Do the residual plots suggest any unusually large outliers? Does the leverage plot identify any observations with unusually high leverage?

par(mfrow = c(2, 2))
plot(fit2)

As before, the plot of residuals versus fitted values indicates the presence of mild non linearity in the data. The plot of standardized residuals versus leverage indicates the presence of a few outliers (higher than 2 or lower than -2) and one high leverage point (point 14).

(e) Fit some models with interactions as described in the lab. Do any interactions appear to be statistically significant?

From the correlation matrix, we obtained the two highest correlated pairs and used them in picking interaction effects.

fit3 <- lm(mpg ~ cylinders * displacement+displacement * weight, data = Auto[, 1:8])
summary(fit3)

Call:
lm(formula = mpg ~ cylinders * displacement + displacement * 
    weight, data = Auto[, 1:8])

Residuals:
     Min       1Q   Median       3Q      Max 
-13.2934  -2.5184  -0.3476   1.8399  17.7723 

Coefficients:
                         Estimate Std. Error t value Pr(>|t|)    
(Intercept)             5.262e+01  2.237e+00  23.519  < 2e-16 ***
cylinders               7.606e-01  7.669e-01   0.992    0.322    
displacement           -7.351e-02  1.669e-02  -4.403 1.38e-05 ***
weight                 -9.888e-03  1.329e-03  -7.438 6.69e-13 ***
cylinders:displacement -2.986e-03  3.426e-03  -0.872    0.384    
displacement:weight     2.128e-05  5.002e-06   4.254 2.64e-05 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 4.103 on 386 degrees of freedom
Multiple R-squared:  0.7272,    Adjusted R-squared:  0.7237 
F-statistic: 205.8 on 5 and 386 DF,  p-value: < 2.2e-16

From the p-values, we can see that the interaction between displacement and weight is statistically signifcant, while the interactiion between cylinders and displacement is not.

Problem 10

This question should be answered using the Carseats data set.

library(ISLR2)
attach(Carseats)
fit<-lm(Sales ~ Price + Urban + US, data = Carseats)
summary(fit)

Call:
lm(formula = Sales ~ Price + Urban + US, data = Carseats)

Residuals:
    Min      1Q  Median      3Q     Max 
-6.9206 -1.6220 -0.0564  1.5786  7.0581 

Coefficients:
             Estimate Std. Error t value Pr(>|t|)    
(Intercept) 13.043469   0.651012  20.036  < 2e-16 ***
Price       -0.054459   0.005242 -10.389  < 2e-16 ***
UrbanYes    -0.021916   0.271650  -0.081    0.936    
USYes        1.200573   0.259042   4.635 4.86e-06 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 2.472 on 396 degrees of freedom
Multiple R-squared:  0.2393,    Adjusted R-squared:  0.2335 
F-statistic: 41.52 on 3 and 396 DF,  p-value: < 2.2e-16

(a) Fit a multiple regression model to predict Sales using Price, Urban, and US.

(b) Provide an interpretation of each coefficient in the model. Becareful—some of the variables in the model are qualitative!

From the table above, Price and US, are significant predictors of Sales. For every $1 increase in Price, sales decrease by $54. Sales at US stores are $1200 higher than stores outside of the US. Urban has no effect on sales (p=0.936)

(c) Write out the model in equation form, being careful to handle the qualitative variables properly.

$Sales = 13.043469 - 0.054459 * x_{Price} - 0.021916 * x_{Urban} + 1.200573 * x_{USYes}

(d) For which of the predictors can you reject the null hypothesis H0 : βj = 0?

Price and US

(e) On the basis of your response to the previous question, fit a smaller model that only uses the predictors for which there is evidence of association with the outcome.

fit_sm<-lm(Sales ~ Price + US, data = Carseats)
summary(fit_sm)

Call:
lm(formula = Sales ~ Price + US, data = Carseats)

Residuals:
    Min      1Q  Median      3Q     Max 
-6.9269 -1.6286 -0.0574  1.5766  7.0515 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)    
(Intercept) 13.03079    0.63098  20.652  < 2e-16 ***
Price       -0.05448    0.00523 -10.416  < 2e-16 ***
USYes        1.19964    0.25846   4.641 4.71e-06 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 2.469 on 397 degrees of freedom
Multiple R-squared:  0.2393,    Adjusted R-squared:  0.2354 
F-statistic: 62.43 on 2 and 397 DF,  p-value: < 2.2e-16

(f) How well do the models in (a) and (e) fit the data?

Not great, \(R^2\) only 23%

(g) Using the model from (e), obtain 95 % confidence intervals for the coefficient(s).

confint(fit_sm)
                  2.5 %      97.5 %
(Intercept) 11.79032020 14.27126531
Price       -0.06475984 -0.04419543
USYes        0.69151957  1.70776632

(h) Is there evidence of outliers or high leverage observations in the model from (e)?

par(mfrow=c(2,2))
plot(fit_sm)

influence.measures(fit_sm)
Influence measures of
     lm(formula = Sales ~ Price + US, data = Carseats) :

       dfb.1_  dfb.Pric  dfb.USYs     dffit cov.r   cook.d     hat inf
1   -4.68e-03  4.96e-03  0.026900  0.045975 1.007 7.05e-04 0.00392    
2    4.17e-02 -4.42e-02  0.025407  0.058551 1.014 1.14e-03 0.00900    
3    5.65e-03 -5.98e-03  0.003187  0.007653 1.018 1.96e-05 0.00995    
4   -2.49e-02  2.64e-02 -0.024827 -0.047236 1.010 7.45e-04 0.00564    
5    4.24e-04 -2.32e-02  0.053707 -0.069298 1.011 1.60e-03 0.00793    
6    1.84e-02 -1.95e-02  0.008746  0.023345 1.020 1.82e-04 0.01288    
7   -8.32e-03  2.66e-03  0.014024 -0.017881 1.015 1.07e-04 0.00720    
8   -1.08e-02  1.14e-02  0.062068  0.106079 0.990 3.73e-03 0.00392    
9    8.04e-04  2.29e-03 -0.007383  0.009329 1.015 2.91e-05 0.00750    
10   1.63e-02 -1.73e-02 -0.040957 -0.072613 1.002 1.76e-03 0.00411    
11   3.11e-03 -3.29e-03  0.003613  0.006628 1.013 1.47e-05 0.00514    
12   5.30e-02 -5.61e-02  0.046280  0.091572 1.004 2.79e-03 0.00621    
13   1.11e-02 -3.13e-02  0.046932 -0.064402 1.014 1.38e-03 0.00922    
14   3.56e-02 -3.77e-02  0.023549  0.052047 1.013 9.04e-04 0.00813    
15  -3.26e-03  3.45e-03  0.050559  0.085405 0.997 2.43e-03 0.00388    
16  -4.70e-02  9.20e-02 -0.102546  0.152191 1.003 7.70e-03 0.01109    
17   7.83e-03 -1.85e-03 -0.014742  0.018612 1.014 1.16e-04 0.00711    
18  -6.03e-02  6.38e-02  0.074948  0.146807 0.979 7.12e-03 0.00478    
19   1.36e-01 -1.44e-01  0.059885  0.168012 1.008 9.39e-03 0.01456    
20  -3.72e-03  3.93e-03  0.016187  0.027875 1.010 2.60e-04 0.00395    
21   7.89e-03 -8.35e-03 -0.009809 -0.019215 1.012 1.23e-04 0.00478    
22   2.44e-02 -2.59e-02  0.059391  0.100708 0.993 3.37e-03 0.00415    
23   3.63e-03 -9.00e-03  0.012416 -0.017355 1.017 1.01e-04 0.00964    
24  -1.87e-02  5.22e-03  0.033221 -0.042137 1.013 5.93e-04 0.00715    
25   6.40e-03 -6.77e-03  0.031478  0.052699 1.006 9.26e-04 0.00394    
26   2.39e-01 -1.77e-01 -0.165700  0.281894 0.969 2.61e-02 0.01162   *
27  -1.43e-02  1.51e-02  0.017735  0.034739 1.011 4.03e-04 0.00478    
28  -3.27e-02  1.16e-02  0.052321 -0.067102 1.010 1.50e-03 0.00726    
29  -9.67e-02  1.02e-01 -0.096306 -0.183233 0.969 1.11e-02 0.00564   *
30  -1.04e-02  1.10e-02 -0.013639 -0.024475 1.012 2.00e-04 0.00486    
31   1.71e-01 -1.17e-01 -0.141670  0.218753 0.981 1.58e-02 0.00983    
32  -1.33e-02  1.41e-02  0.016587  0.032490 1.011 3.53e-04 0.00478    
33   9.32e-03 -9.86e-03 -0.007971 -0.017421 1.013 1.01e-04 0.00570    
34  -1.38e-02  1.46e-02  0.021925  0.040957 1.009 5.60e-04 0.00444    
35   4.19e-02 -4.44e-02 -0.066749 -0.124690 0.986 5.15e-03 0.00444    
36   3.51e-02 -3.71e-02  0.033353  0.064275 1.008 1.38e-03 0.00582    
37   2.96e-02 -1.57e-02 -0.034951  0.047421 1.013 7.51e-04 0.00792    
38  -1.82e-02  1.93e-02 -0.050674 -0.085522 0.998 2.43e-03 0.00408    
39  -1.85e-02  9.12e-03  0.023720 -0.031589 1.014 3.33e-04 0.00768    
40   1.91e-02 -4.73e-02  0.065259 -0.091217 1.011 2.77e-03 0.00964    
41  -5.79e-03 -4.28e-02  0.115212 -0.146969 0.994 7.17e-03 0.00769    
42   5.12e-03  1.46e-02 -0.047057  0.059461 1.012 1.18e-03 0.00750    
43  -1.14e-01  1.04e-01  0.030773 -0.113868 1.051 4.33e-03 0.04334   *
44   3.94e-02 -4.17e-02 -0.039972 -0.082542 1.003 2.27e-03 0.00520    
45  -8.73e-02  9.25e-02 -0.079479 -0.155182 0.984 7.97e-03 0.00601    
46   3.43e-02 -3.63e-02 -0.032811 -0.069024 1.006 1.59e-03 0.00536    
47   7.77e-02 -8.23e-02  0.035510  0.097200 1.016 3.15e-03 0.01371    
48  -4.46e-02  1.42e-02  0.075147 -0.095815 1.005 3.06e-03 0.00720    
49  -9.20e-02  5.23e-02  0.101053 -0.139932 0.998 6.50e-03 0.00818    
50  -1.00e-01  1.74e-01 -0.168150  0.263200 0.979 2.28e-02 0.01255   *
51  -5.01e-02  5.30e-02 -0.108307 -0.184702 0.953 1.12e-02 0.00422   *
52  -4.39e-02  1.40e-02  0.074057 -0.094426 1.006 2.97e-03 0.00720    
53  -7.01e-03  7.42e-03  0.010212  0.019367 1.012 1.25e-04 0.00454    
54   1.47e-03 -1.56e-03 -0.012355 -0.020981 1.011 1.47e-04 0.00390    
55   3.29e-02 -3.49e-02 -0.020405 -0.051351 1.012 8.80e-04 0.00719    
56  -3.07e-02  3.25e-02  0.013392  0.041403 1.017 5.73e-04 0.01008    
57   1.24e-01 -8.99e-02 -0.090119  0.149028 1.004 7.38e-03 0.01107    
58  -5.06e-02 -1.52e-02  0.159478 -0.198393 0.974 1.30e-02 0.00708   *
59  -3.60e-02  3.81e-02 -0.050452 -0.089617 1.000 2.67e-03 0.00473    
60  -1.80e-02 -6.85e-05  0.044160 -0.055073 1.011 1.01e-03 0.00704    
61  -3.97e-03  4.21e-03  0.011643  0.020422 1.011 1.39e-04 0.00405    
62   2.00e-03 -7.10e-04 -0.003202  0.004107 1.015 5.64e-06 0.00726    
63   6.84e-02 -7.24e-02 -0.073995 -0.150060 0.979 7.44e-03 0.00505    
64  -3.32e-03  3.51e-03 -0.004090 -0.007419 1.013 1.84e-05 0.00500    
65  -7.96e-03  8.43e-03 -0.011997 -0.021106 1.012 1.49e-04 0.00461    
66   2.57e-04 -1.40e-02  0.032576 -0.042033 1.014 5.90e-04 0.00793    
67   2.33e-02 -1.54e-02 -0.020447  0.030757 1.016 3.16e-04 0.00941    
68   1.54e-03 -1.63e-03  0.015803  0.026459 1.010 2.34e-04 0.00389    
69  -9.11e-02  9.65e-02  0.092526  0.191069 0.961 1.20e-02 0.00520   *
70   8.26e-03 -4.55e-03 -0.009407  0.012891 1.016 5.55e-05 0.00804    
71   9.02e-03 -9.55e-03  0.009932  0.018437 1.012 1.14e-04 0.00530    
72  -1.20e-02  1.27e-02  0.005935  0.016906 1.016 9.55e-05 0.00882    
73  -1.14e-02 -2.11e-03  0.032783 -0.040790 1.013 5.56e-04 0.00706    
74   4.23e-02 -4.47e-02  0.063665  0.112006 0.992 4.16e-03 0.00461    
75   9.70e-03 -1.03e-02 -0.008766 -0.018794 1.013 1.18e-04 0.00553    
76  -1.35e-02  1.43e-02 -0.010908 -0.022176 1.014 1.64e-04 0.00664    
77   8.56e-03 -9.07e-03  0.003911  0.010705 1.022 3.83e-05 0.01371    
78  -3.81e-02  4.04e-02 -0.027729 -0.058767 1.011 1.15e-03 0.00735    
79   4.37e-02 -4.63e-02 -0.026032 -0.066875 1.011 1.49e-03 0.00744    
80   3.12e-02 -2.10e-02 -0.026604  0.040542 1.016 5.49e-04 0.00962    
81  -5.93e-02  6.28e-02 -0.032660 -0.079511 1.013 2.11e-03 0.01029    
82  -3.25e-04  1.77e-02 -0.041157  0.053105 1.013 9.42e-04 0.00793    
83  -9.01e-02  9.54e-02  0.069639  0.158314 0.983 8.29e-03 0.00608    
84  -8.75e-02  9.26e-02 -0.076361 -0.151090 0.986 7.56e-03 0.00621    
85  -2.32e-02 -2.57e-02  0.117290 -0.146702 0.993 7.14e-03 0.00727    
86   1.98e-02 -2.59e-03 -0.042095  0.052754 1.012 9.29e-04 0.00706    
87  -1.52e-02  5.15e-02 -0.084653  0.114162 1.005 4.34e-03 0.00885    
88  -3.25e-02  3.44e-02  0.063451  0.115270 0.988 4.41e-03 0.00425    
89  -7.67e-03  8.12e-03 -0.024896 -0.041860 1.008 5.85e-04 0.00403    
90   9.98e-03  6.11e-03 -0.038798  0.048336 1.012 7.80e-04 0.00716    
91  -4.22e-02  1.98e-02  0.056206 -0.074210 1.010 1.84e-03 0.00758    
92  -2.87e-02  3.04e-02 -0.055925 -0.096001 0.996 3.06e-03 0.00431    
93  -3.76e-03 -1.61e-02  0.047332 -0.060078 1.012 1.20e-03 0.00759    
94   2.89e-02 -1.28e-02 -0.040262  0.052732 1.012 9.28e-04 0.00749    
95  -3.39e-02  3.59e-02 -0.021184 -0.048144 1.014 7.74e-04 0.00870    
96   1.50e-02 -1.58e-02 -0.007960 -0.021759 1.016 1.58e-04 0.00824    
97  -3.02e-02  3.20e-02  0.034931  0.069602 1.005 1.61e-03 0.00491    
98  -2.45e-03  2.59e-03  0.003569  0.006769 1.012 1.53e-05 0.00454    
99  -4.31e-02  4.57e-02  0.075690  0.139378 0.979 6.42e-03 0.00434    
100 -2.81e-02  2.98e-02 -0.054829 -0.094121 0.996 2.95e-03 0.00431    
101 -3.83e-02  4.06e-02 -0.067982 -0.117568 0.988 4.58e-03 0.00440    
102 -3.19e-03 -1.41e-03  0.011111 -0.013829 1.015 6.39e-05 0.00712    
103 -6.14e-02  3.59e-02  0.065142 -0.091186 1.008 2.77e-03 0.00833    
104 -6.68e-02  7.07e-02 -0.063497 -0.122366 0.994 4.97e-03 0.00582    
105  7.49e-03 -1.86e-02  0.025613 -0.035801 1.016 4.28e-04 0.00964    
106 -5.49e-02  5.81e-02 -0.054638 -0.103954 0.999 3.59e-03 0.00564    
107  4.91e-02 -1.16e-01  0.153162 -0.216141 0.982 1.54e-02 0.00986    
108  2.26e-02 -7.21e-03 -0.038049  0.048514 1.012 7.86e-04 0.00720    
109 -7.99e-02  3.75e-02  0.106486 -0.140596 0.996 6.56e-03 0.00758    
110  2.63e-02 -1.77e-02 -0.022397  0.034131 1.016 3.89e-04 0.00962    
111  7.17e-04 -7.59e-04  0.016421  0.027544 1.010 2.53e-04 0.00388    
112 -1.72e-02  1.82e-02  0.008254  0.024001 1.016 1.92e-04 0.00912    
113  5.00e-03 -5.29e-03 -0.010986 -0.019708 1.011 1.30e-04 0.00418    
114  1.08e-02 -1.14e-02 -0.018929 -0.034856 1.010 4.06e-04 0.00434    
115  7.51e-03 -7.95e-03  0.013312  0.023021 1.011 1.77e-04 0.00440    
116 -2.64e-03  3.30e-02 -0.071598  0.092975 1.008 2.88e-03 0.00806    
117  2.17e-04 -1.19e-02  0.027509 -0.035495 1.014 4.21e-04 0.00793    
118  1.60e-02  9.82e-03 -0.062359  0.077691 1.008 2.01e-03 0.00716    
119 -1.84e-02  1.94e-02 -0.020211 -0.037517 1.011 4.70e-04 0.00530    
120 -1.02e-03  1.09e-03  0.001633  0.003050 1.012 3.11e-06 0.00444    
121  2.58e-03 -2.73e-03 -0.003211 -0.006289 1.012 1.32e-05 0.00478    
122  5.30e-02 -5.61e-02  0.036177  0.078845 1.010 2.07e-03 0.00786    
123 -1.05e-02  1.11e-02 -0.022716 -0.038739 1.009 5.01e-04 0.00422    
124 -7.51e-02  7.96e-02  0.031820  0.100391 1.011 3.36e-03 0.01042    
125  1.50e-02  1.24e-02 -0.065936  0.082284 1.008 2.26e-03 0.00721    
126 -6.68e-02  5.84e-02  0.025165 -0.068356 1.033 1.56e-03 0.02597   *
127 -5.66e-02  6.00e-02  0.061284  0.124281 0.990 5.12e-03 0.00505    
128 -9.16e-04  9.69e-04 -0.020980 -0.035190 1.009 4.13e-04 0.00388    
129  1.80e-02 -1.90e-02 -0.035135 -0.063829 1.005 1.36e-03 0.00425    
130  4.32e-02 -4.57e-02 -0.023827 -0.063794 1.012 1.36e-03 0.00796    
131 -5.30e-02  5.61e-02 -0.027877 -0.069716 1.015 1.62e-03 0.01099    
132 -3.88e-02  2.43e-02  0.037317 -0.054076 1.014 9.76e-04 0.00883    
133 -4.25e-02  4.50e-02  0.038402  0.082328 1.004 2.26e-03 0.00553    
134 -2.14e-02  2.26e-02 -0.021291 -0.040509 1.011 5.48e-04 0.00564    
135  5.94e-03 -3.28e-02  0.062996 -0.082961 1.010 2.30e-03 0.00835    
136  3.25e-03 -3.44e-03 -0.018650 -0.031874 1.010 3.39e-04 0.00392    
137 -8.34e-03 -6.91e-03  0.036690 -0.045786 1.013 7.00e-04 0.00721    
138 -6.53e-04 -2.88e-04  0.002276 -0.002833 1.015 2.68e-06 0.00712    
139  1.26e-02 -1.33e-02  0.030537  0.051781 1.007 8.95e-04 0.00415    
140  5.94e-02 -6.29e-02  0.051823  0.102538 1.001 3.50e-03 0.00621    
141  1.16e-02 -1.23e-02 -0.016939 -0.032125 1.010 3.45e-04 0.00454    
142 -1.70e-03  9.36e-03 -0.017990  0.023691 1.016 1.88e-04 0.00835    
143  1.45e-03 -6.43e-04 -0.002016  0.002640 1.015 2.33e-06 0.00749    
144  1.75e-01 -1.85e-01 -0.066058 -0.225796 0.988 1.69e-02 0.01186    
145  1.07e-02  2.16e-02 -0.077035  0.096957 1.005 3.13e-03 0.00741    
146 -1.41e-04  1.49e-04  0.013728  0.023094 1.010 1.78e-04 0.00388    
147  5.33e-03 -2.94e-02  0.056471 -0.074367 1.011 1.85e-03 0.00835    
148 -4.92e-03  5.21e-03  0.041300  0.070133 1.002 1.64e-03 0.00390    
149 -2.24e-02  2.37e-02 -0.022256 -0.042343 1.011 5.99e-04 0.00564    
150  4.84e-02 -5.12e-02  0.033017  0.071958 1.011 1.73e-03 0.00786    
151  5.65e-03 -5.98e-03  0.037533  0.062803 1.004 1.31e-03 0.00391    
152  2.42e-02 -2.56e-02  0.033878  0.060177 1.007 1.21e-03 0.00473    
153 -3.52e-04  1.92e-02 -0.044538  0.057467 1.012 1.10e-03 0.00793    
154  3.49e-03 -3.69e-03 -0.001732 -0.004935 1.017 8.14e-06 0.00882    
155 -7.46e-03  7.90e-03 -0.020735 -0.034995 1.009 4.09e-04 0.00408    
156 -7.55e-02  6.12e-02  0.039681 -0.081521 1.021 2.22e-03 0.01611    
157 -7.26e-02  1.13e-01 -0.089947  0.153612 1.012 7.86e-03 0.01536    
158  1.93e-02 -2.04e-02  0.014496  0.030297 1.014 3.07e-04 0.00710    
159  1.73e-02 -1.83e-02  0.067505  0.113196 0.987 4.25e-03 0.00398    
160  4.87e-03 -3.93e-03 -0.002611  0.005286 1.024 9.34e-06 0.01571   *
161 -3.16e-02  5.90e-03  0.063142 -0.079398 1.008 2.10e-03 0.00708    
162  9.15e-02 -9.69e-02 -0.033629 -0.117238 1.012 4.58e-03 0.01224    
163  2.24e-02 -3.90e-02  0.037646 -0.058926 1.018 1.16e-03 0.01255    
164 -2.79e-02  1.08e-02  0.042604 -0.054993 1.012 1.01e-03 0.00733    
165 -3.29e-02  3.49e-02  0.023187  0.054876 1.011 1.01e-03 0.00650    
166  2.14e-01 -2.27e-01 -0.040295 -0.243757 1.022 1.98e-02 0.02857   *
167  9.36e-04 -9.91e-04 -0.000801 -0.001751 1.013 1.02e-06 0.00570    
168 -3.56e-02  2.27e-02  0.033142 -0.048613 1.015 7.89e-04 0.00901    
169  5.62e-03  1.69e-03 -0.017724  0.022049 1.014 1.62e-04 0.00708    
170  4.71e-02 -4.98e-02  0.024765  0.061933 1.016 1.28e-03 0.01099    
171 -2.01e-04  2.13e-04  0.003114  0.005260 1.011 9.25e-06 0.00388    
172  6.42e-02 -6.79e-02  0.023151  0.075234 1.027 1.89e-03 0.02101   *
173  4.38e-03 -4.64e-03  0.012182  0.020560 1.011 1.41e-04 0.00408    
174  7.98e-03 -8.45e-03 -0.012712 -0.023746 1.011 1.88e-04 0.00444    
175  1.41e-01 -1.86e-01  0.093690 -0.212431 1.027 1.50e-02 0.02969   *
176  5.40e-03  8.03e-03 -0.032149  0.040325 1.013 5.43e-04 0.00733    
177  7.02e-03 -7.43e-03 -0.003063 -0.009471 1.018 3.00e-05 0.01008    
178  2.55e-02 -2.70e-02  0.022222  0.043969 1.012 6.46e-04 0.00621    
179  2.46e-02 -2.61e-02  0.014249  0.033756 1.016 3.81e-04 0.00963    
180 -8.62e-05  9.13e-05 -0.001975 -0.003313 1.011 3.67e-06 0.00388    
181  3.08e-02 -3.26e-02 -0.015840 -0.044200 1.015 6.52e-04 0.00852    
182 -1.93e-02  1.28e-02  0.016936 -0.025475 1.017 2.17e-04 0.00941    
183  6.66e-03 -1.50e-02  0.019119 -0.027245 1.017 2.48e-04 0.01009    
184 -4.05e-02  4.29e-02 -0.053073 -0.095243 0.998 3.02e-03 0.00486    
185  1.62e-02 -1.71e-02  0.016116  0.030662 1.012 3.14e-04 0.00564    
186  1.33e-02 -1.41e-02  0.025930  0.044512 1.008 6.61e-04 0.00431    
187  1.14e-02 -8.09e-03 -0.008726  0.014033 1.018 6.58e-05 0.01055    
188 -4.59e-02  2.75e-02  0.047046 -0.066596 1.012 1.48e-03 0.00849    
189 -1.78e-03  1.20e-03  0.001519 -0.002315 1.017 1.79e-06 0.00962    
190  3.70e-02 -3.92e-02  0.055752  0.098084 0.997 3.20e-03 0.00461    
191  7.95e-04 -8.41e-04  0.000979  0.001776 1.013 1.05e-06 0.00500    
192 -8.64e-02  9.14e-02  0.023164  0.103201 1.022 3.55e-03 0.01804    
193 -1.15e-02  7.32e-03  0.010681 -0.015667 1.017 8.20e-05 0.00901    
194  7.28e-02 -7.70e-02  0.069173  0.133306 0.991 5.89e-03 0.00582    
195  2.48e-04 -2.63e-04 -0.000395 -0.000739 1.012 1.82e-07 0.00444    
196 -1.54e-02  1.63e-02 -0.060368 -0.101228 0.992 3.40e-03 0.00398    
197  3.80e-02 -4.03e-02 -0.041172 -0.083496 1.002 2.32e-03 0.00505    
198  2.52e-02 -6.24e-02  0.085999 -0.120208 1.006 4.81e-03 0.00964    
199  3.32e-02 -3.51e-02 -0.052839 -0.098706 0.996 3.24e-03 0.00444    
200  7.07e-03 -7.48e-03 -0.013803 -0.025075 1.011 2.10e-04 0.00425    
201 -7.22e-03  1.34e-02 -0.014074  0.021332 1.019 1.52e-04 0.01165    
202 -1.07e-03  3.63e-03 -0.005954  0.008029 1.017 2.15e-05 0.00885    
203  3.27e-02 -3.47e-02 -0.043953 -0.084687 1.001 2.39e-03 0.00466    
204  5.85e-02 -9.10e-02  0.072448 -0.123728 1.016 5.10e-03 0.01536    
205  7.50e-03  2.14e-02 -0.068894  0.087054 1.008 2.53e-03 0.00750    
206  5.57e-04 -2.49e-03  0.004529 -0.006009 1.016 1.21e-05 0.00850    
207  1.92e-02 -2.04e-02 -0.007070 -0.024649 1.020 2.03e-04 0.01224    
208  1.11e-02 -6.49e-03 -0.011796  0.016512 1.016 9.11e-05 0.00833    
209 -9.27e-02  7.69e-02  0.044481 -0.098207 1.022 3.22e-03 0.01823    
210 -1.39e-01  1.47e-01 -0.104454 -0.218309 0.965 1.57e-02 0.00710   *
211  1.60e-02 -1.69e-02 -0.046788 -0.082065 0.999 2.24e-03 0.00405    
212 -4.40e-03  4.66e-03  0.025261  0.043173 1.008 6.22e-04 0.00392    
213  3.40e-02 -3.60e-02  0.055324  0.096465 0.997 3.09e-03 0.00450    
214 -2.84e-02  3.01e-02  0.021960  0.049923 1.011 8.32e-04 0.00608    
215 -2.85e-02  3.02e-02 -0.055612 -0.095464 0.996 3.03e-03 0.00431    
216  9.00e-02 -9.52e-02 -0.055731 -0.140250 0.994 6.53e-03 0.00719    
217 -7.24e-03  1.42e-02 -0.015790  0.023434 1.019 1.83e-04 0.01109    
218 -3.61e-02  6.74e-03  0.072173 -0.090753 1.006 2.74e-03 0.00708    
219 -5.20e-03  5.51e-03  0.029883  0.051072 1.007 8.70e-04 0.00392    
220  1.79e-03 -1.89e-03  0.040903  0.068607 1.002 1.57e-03 0.00388    
221 -1.82e-02  1.93e-02  0.045822  0.081238 1.000 2.20e-03 0.00411    
222 -1.30e-02  4.63e-03  0.020888 -0.026789 1.014 2.40e-04 0.00726    
223 -2.66e-02  2.82e-02  0.015859  0.040743 1.013 5.54e-04 0.00744    
224  2.65e-02 -2.81e-02 -0.058293 -0.104568 0.992 3.63e-03 0.00418    
225  1.36e-02 -2.93e-02  0.036060 -0.051899 1.016 9.00e-04 0.01032    
226 -7.06e-02  5.22e-02  0.048879 -0.083155 1.015 2.31e-03 0.01162    
227  6.61e-03  9.84e-03 -0.039389  0.049406 1.013 8.15e-04 0.00733    
228 -4.91e-04  5.20e-04 -0.000605 -0.001098 1.013 4.03e-07 0.00500    
229 -1.87e-03  1.98e-03  0.000636  0.002349 1.021 1.84e-06 0.01345    
230  9.54e-02 -7.60e-02 -0.053159  0.104548 1.017 3.65e-03 0.01494    
231 -1.86e-02 -7.06e-05  0.045533 -0.056785 1.011 1.08e-03 0.00704    
232  7.97e-03  1.19e-02 -0.047467  0.059539 1.011 1.18e-03 0.00733    
233  4.46e-02 -4.73e-02  0.072701  0.126765 0.985 5.32e-03 0.00450    
234 -2.48e-03  2.63e-03  0.014239  0.024336 1.010 1.98e-04 0.00392    
235 -2.21e-02  2.34e-02  0.032191  0.061051 1.006 1.24e-03 0.00454    
236  1.87e-02 -1.97e-02 -0.021587 -0.043012 1.010 6.18e-04 0.00491    
237  6.97e-03 -7.38e-03  0.015067  0.025694 1.011 2.21e-04 0.00422    
238 -4.07e-02  4.31e-02  0.038894  0.081820 1.004 2.23e-03 0.00536    
239 -6.78e-03  2.59e-02 -0.044750  0.059853 1.013 1.20e-03 0.00867    
240  3.79e-03 -4.02e-03 -0.058776 -0.099286 0.992 3.27e-03 0.00388    
241  2.13e-02  2.36e-02 -0.107810  0.134844 0.996 6.04e-03 0.00727    
242  1.13e-01 -7.09e-02 -0.108859  0.157746 0.995 8.26e-03 0.00883    
243  5.92e-03 -1.81e-02  0.028414 -0.038648 1.016 4.99e-04 0.00903    
244 -2.31e-03  2.45e-03 -0.006427 -0.010846 1.012 3.93e-05 0.00408    
245  2.71e-02 -1.44e-02 -0.032008  0.043427 1.014 6.30e-04 0.00792    
246  1.32e-02 -1.40e-02  0.009317  0.020024 1.015 1.34e-04 0.00760    
247 -5.31e-02  5.62e-02 -0.039915 -0.083421 1.007 2.32e-03 0.00710    
248 -4.49e-03  7.57e-03 -0.006928  0.011081 1.021 4.10e-05 0.01320    
249 -4.34e-02  4.60e-02 -0.053479 -0.097012 0.998 3.13e-03 0.00500    
250 -1.41e-02 -4.23e-03  0.044308 -0.055120 1.012 1.01e-03 0.00708    
251 -1.10e-01  1.17e-01  0.045283  0.145780 1.004 7.07e-03 0.01077    
252  4.11e-02 -4.35e-02 -0.047559 -0.094763 0.999 2.99e-03 0.00491    
253  1.45e-02  4.35e-03 -0.045583  0.056706 1.011 1.07e-03 0.00708    
254  8.20e-03 -8.68e-03 -0.028756 -0.049949 1.007 8.32e-04 0.00400    
255 -2.36e-02  2.50e-02  0.034364  0.065172 1.005 1.42e-03 0.00454    
256 -6.17e-02  6.53e-02 -0.035686 -0.084540 1.012 2.38e-03 0.00963    
257  1.31e-02 -2.57e-02  0.028624 -0.042481 1.018 6.03e-04 0.01109    
258  2.11e-03 -2.24e-03  0.008266  0.013861 1.011 6.42e-05 0.00398    
259 -1.98e-01  1.48e-01  0.134017 -0.231280 0.986 1.77e-02 0.01191    
260 -5.02e-02  5.32e-02 -0.058371 -0.107089 0.996 3.81e-03 0.00514    
261 -1.36e-02  1.44e-02 -0.016766 -0.030414 1.011 3.09e-04 0.00500    
262  2.02e-03 -2.14e-03 -0.031361 -0.052975 1.006 9.36e-04 0.00388    
263  8.27e-03 -8.75e-03 -0.009570 -0.019068 1.012 1.21e-04 0.00491    
264 -2.87e-04  3.04e-04 -0.002957 -0.004951 1.011 8.19e-06 0.00389    
265 -4.77e-02  5.05e-02  0.018023  0.061606 1.017 1.27e-03 0.01186    
266  1.88e-02 -1.99e-02 -0.027350 -0.051871 1.008 8.98e-04 0.00454    
267  3.80e-03 -4.02e-03  0.014837  0.024880 1.010 2.07e-04 0.00398    
268 -8.99e-03  9.52e-03 -0.035159 -0.058956 1.005 1.16e-03 0.00398    
269 -1.45e-02  6.03e-03  0.021055 -0.027369 1.014 2.50e-04 0.00740    
270 -3.23e-02  4.65e-02 -0.031065  0.058429 1.026 1.14e-03 0.01919   *
271  1.21e-01 -8.24e-02 -0.100195  0.154710 0.999 7.95e-03 0.00983    
272 -3.60e-02  8.49e-03  0.067793 -0.085589 1.007 2.44e-03 0.00711    
273  1.81e-01 -1.51e-01 -0.085270  0.190967 1.012 1.21e-02 0.01869    
274  1.24e-02 -1.32e-02  0.008231  0.018192 1.016 1.11e-04 0.00813    
275  9.39e-04 -9.94e-04 -0.007876 -0.013374 1.011 5.98e-05 0.00390    
276  4.56e-03 -4.83e-03 -0.005280 -0.010522 1.012 3.70e-05 0.00491    
277  2.34e-03 -2.48e-03 -0.003142 -0.006054 1.012 1.22e-05 0.00466    
278 -2.52e-03  2.67e-03  0.005550  0.009956 1.012 3.31e-05 0.00418    
279 -3.39e-02  3.59e-02  0.016301  0.047401 1.015 7.50e-04 0.00912    
280  7.43e-02 -7.87e-02 -0.028858 -0.096700 1.013 3.12e-03 0.01149    
281  8.00e-02 -8.47e-02 -0.047612 -0.122315 1.000 4.97e-03 0.00744    
282  2.58e-02 -2.73e-02  0.041955  0.073155 1.003 1.78e-03 0.00450    
283 -6.70e-02  1.08e-01 -0.091968  0.152008 1.010 7.69e-03 0.01424    
284 -1.13e-02 -3.41e-03  0.035754 -0.044478 1.013 6.61e-04 0.00708    
285 -2.15e-02  1.29e-02  0.022063 -0.031231 1.015 3.26e-04 0.00849    
286 -5.84e-03  6.18e-03  0.007260  0.014220 1.012 6.76e-05 0.00478    
287 -1.69e-03  1.78e-03 -0.008291 -0.013880 1.011 6.44e-05 0.00394    
288 -1.26e-01  1.34e-01 -0.059874 -0.159817 1.006 8.49e-03 0.01288    
289 -1.92e-02  1.12e-02  0.020386 -0.028536 1.015 2.72e-04 0.00833    
290 -9.69e-02  1.03e-01  0.039845  0.128274 1.007 5.48e-03 0.01077    
291  9.78e-03 -1.04e-02  0.013705  0.024344 1.011 1.98e-04 0.00473    
292 -4.88e-02  3.33e-02  0.040480 -0.062505 1.015 1.30e-03 0.00983    
293  5.69e-02 -6.02e-02  0.028071  0.073027 1.017 1.78e-03 0.01210    
294  9.82e-02 -6.70e-02 -0.081428  0.125733 1.005 5.26e-03 0.00983    
295  5.55e-02 -5.88e-02  0.061140  0.113493 0.995 4.28e-03 0.00530    
296  4.21e-02 -4.45e-02 -0.035992 -0.078664 1.005 2.06e-03 0.00570    
297 -3.42e-03  3.62e-03  0.010022  0.017579 1.011 1.03e-04 0.00405    
298 -5.76e-02  6.10e-02 -0.086729 -0.152582 0.975 7.68e-03 0.00461   *
299 -9.38e-03  7.01e-02 -0.142836  0.186752 0.984 1.15e-02 0.00820    
300  6.76e-03 -7.16e-03  0.006432  0.012395 1.013 5.13e-05 0.00582    
301 -3.87e-03  4.10e-03 -0.004260 -0.007907 1.013 2.09e-05 0.00530    
302 -5.06e-02  5.36e-02 -0.034543 -0.075284 1.010 1.89e-03 0.00786    
303 -1.64e-02  1.74e-02 -0.045569 -0.076905 1.001 1.97e-03 0.00408    
304  1.70e-02 -1.80e-02  0.018706  0.034724 1.011 4.03e-04 0.00530    
305 -7.03e-02  7.44e-02  0.071362  0.147363 0.982 7.18e-03 0.00520    
306 -1.22e-02  1.30e-02  0.014163  0.028221 1.011 2.66e-04 0.00491    
307  2.91e-02 -3.08e-02 -0.031445 -0.063769 1.007 1.36e-03 0.00505    
308 -3.74e-03 -3.10e-03  0.016448 -0.020526 1.014 1.41e-04 0.00721    
309 -1.40e-02  1.48e-02  0.027347  0.049680 1.007 8.24e-04 0.00425    
310  3.94e-02 -4.17e-02  0.022202  0.053321 1.016 9.49e-04 0.00995    
311 -1.76e-01  1.86e-01  0.055491  0.217224 0.999 1.56e-02 0.01473    
312  1.10e-02 -1.16e-02 -0.012716 -0.025337 1.012 2.14e-04 0.00491    
313  1.12e-03 -1.19e-03 -0.001075 -0.002261 1.013 1.71e-06 0.00536    
314 -4.64e-02  3.99e-02  0.018838 -0.047835 1.031 7.64e-04 0.02316   *
315 -5.12e-03  5.43e-03  0.007468  0.014163 1.012 6.70e-05 0.00454    
316 -6.58e-02  6.97e-02  0.018456  0.079294 1.022 2.10e-03 0.01705    
317  1.97e-01 -2.08e-01  0.093278  0.248981 0.985 2.05e-02 0.01288    
318 -5.33e-03  1.50e-02 -0.022520  0.030903 1.016 3.19e-04 0.00922    
319 -3.15e-02  3.33e-02  0.042264  0.081433 1.002 2.21e-03 0.00466    
320  2.31e-03 -2.44e-03 -0.003362 -0.006376 1.012 1.36e-05 0.00454    
321  2.58e-03 -2.73e-03 -0.001200 -0.003562 1.017 4.24e-06 0.00943    
322 -4.17e-03  2.37e-03  0.004582 -0.006344 1.016 1.35e-05 0.00818    
323 -4.53e-02  4.79e-02  0.034979  0.079520 1.006 2.11e-03 0.00608    
324  1.96e-02 -2.07e-02  0.027411  0.048689 1.009 7.91e-04 0.00473    
325  9.23e-02 -9.77e-02 -0.045828 -0.130542 1.002 5.67e-03 0.00882    
326  3.27e-02 -3.46e-02  0.049276  0.086691 1.000 2.50e-03 0.00461    
327 -7.92e-03 -1.18e-02  0.047162 -0.059156 1.011 1.17e-03 0.00733    
328 -2.43e-02  2.58e-02 -0.036662 -0.064499 1.005 1.39e-03 0.00461    
329 -2.39e-02  2.53e-02 -0.077556 -0.130402 0.980 5.62e-03 0.00403    
330  4.28e-02 -4.53e-02  0.031133  0.065980 1.011 1.45e-03 0.00735    
331 -2.49e-02  3.27e-03  0.053001 -0.066421 1.010 1.47e-03 0.00706    
332 -4.44e-02  4.70e-02  0.045100  0.093132 1.000 2.89e-03 0.00520    
333 -2.95e-02  3.12e-02 -0.044379 -0.078076 1.002 2.03e-03 0.00461    
334  8.67e-03 -9.18e-03 -0.004787 -0.012816 1.016 5.49e-05 0.00796    
335 -5.74e-02  6.08e-02 -0.034965 -0.080576 1.011 2.17e-03 0.00900    
336 -1.14e-02  1.21e-02 -0.031674 -0.053455 1.006 9.53e-04 0.00408    
337  8.81e-04 -1.77e-03  0.002042 -0.002999 1.019 3.01e-06 0.01083    
338  2.38e-02 -1.17e-02 -0.030481  0.040592 1.014 5.50e-04 0.00768    
339 -3.40e-02  1.74e-02  0.041758 -0.056117 1.012 1.05e-03 0.00779    
340 -3.13e-02  3.31e-02  0.061091  0.110983 0.990 4.09e-03 0.00425    
341 -1.72e-02  1.14e-02  0.015092 -0.022703 1.017 1.72e-04 0.00941    
342 -1.66e-02  1.06e-02  0.015436 -0.022642 1.016 1.71e-04 0.00901    
343 -7.66e-06  8.11e-06  0.000119  0.000200 1.012 1.34e-08 0.00388    
344  5.61e-03 -5.94e-03 -0.024461 -0.042122 1.008 5.92e-04 0.00395    
345 -7.95e-03  8.41e-03  0.015517  0.028190 1.010 2.65e-04 0.00425    
346  1.81e-03 -3.15e-03  0.003038 -0.004755 1.020 7.56e-06 0.01255    
347  6.12e-03  2.63e-02 -0.077015  0.097754 1.006 3.18e-03 0.00759    
348 -6.32e-04  8.30e-05  0.001346 -0.001687 1.015 9.51e-07 0.00706    
349  3.34e-02 -3.53e-02  0.064976  0.111539 0.990 4.13e-03 0.00431    
350  5.41e-03 -5.73e-03  0.005144  0.009912 1.013 3.28e-05 0.00582    
351 -1.33e-02  1.41e-02 -0.010362 -0.021358 1.014 1.52e-04 0.00686    
352  1.85e-02 -1.96e-02  0.030191  0.052642 1.007 9.25e-04 0.00450    
353 -2.49e-02  2.63e-02  0.087167  0.151410 0.969 7.55e-03 0.00400   *
354  4.68e-03 -4.95e-03  0.003777  0.007679 1.014 1.97e-05 0.00664    
355  2.37e-02 -2.51e-02 -0.014112 -0.036253 1.014 4.39e-04 0.00744    
356 -2.91e-02  5.40e-02 -0.056663  0.085884 1.015 2.46e-03 0.01165    
357  1.54e-02 -2.26e-02  0.015622 -0.028768 1.026 2.77e-04 0.01828   *
358  1.12e-01 -1.19e-01  0.053278  0.142211 1.009 6.73e-03 0.01288    
359  3.52e-03 -3.73e-03 -0.054546 -0.092139 0.995 2.82e-03 0.00388    
360  4.32e-02 -4.58e-02 -0.058021 -0.111794 0.992 4.15e-03 0.00466    
361  1.71e-03 -1.81e-03  0.011384  0.019048 1.011 1.21e-04 0.00391    
362  1.20e-03 -1.27e-03  0.001807  0.003180 1.012 3.38e-06 0.00461    
363 -1.66e-02  1.75e-02 -0.046033 -0.077688 1.001 2.01e-03 0.00408    
364  5.01e-02 -1.60e-02 -0.084567  0.107827 1.003 3.87e-03 0.00720    
365 -3.94e-02  4.17e-02  0.048971  0.095925 0.998 3.06e-03 0.00478    
366 -6.57e-02  9.75e-02 -0.070092  0.126352 1.018 5.32e-03 0.01740    
367  1.33e-02 -1.41e-02 -0.013498 -0.027874 1.012 2.60e-04 0.00520    
368  2.63e-01 -2.27e-01 -0.105127  0.270614 1.009 2.43e-02 0.02371   *
369  2.42e-02 -2.56e-02  0.013339  0.032473 1.017 3.52e-04 0.01029    
370 -1.13e-02  1.20e-02  0.039606  0.068796 1.003 1.58e-03 0.00400    
371  1.20e-04 -1.27e-04 -0.001009 -0.001713 1.012 9.81e-07 0.00390    
372  4.11e-03  3.04e-02 -0.081793  0.104339 1.005 3.63e-03 0.00769    
373  2.62e-03 -1.49e-03 -0.002878  0.003985 1.016 5.31e-06 0.00818    
374 -1.08e-02 -2.00e-03  0.031131 -0.038735 1.013 5.01e-04 0.00706    
375 -1.58e-03  1.68e-03  0.024544  0.041460 1.008 5.74e-04 0.00388    
376  4.94e-03  1.41e-02 -0.045379  0.057341 1.012 1.10e-03 0.00750    
377  1.44e-01 -1.52e-01  0.116257  0.236355 0.953 1.83e-02 0.00664   *
378  1.31e-03  5.62e-03 -0.016475  0.020911 1.015 1.46e-04 0.00759    
379  2.91e-03 -3.09e-03 -0.024458 -0.041533 1.008 5.76e-04 0.00390    
380 -2.35e-02  8.35e-03  0.037680 -0.048326 1.013 7.80e-04 0.00726    
381  5.85e-03 -6.19e-03  0.004252  0.009012 1.015 2.71e-05 0.00735    
382  5.88e-02 -6.23e-02 -0.028235 -0.082100 1.011 2.25e-03 0.00912    
383  9.16e-03 -9.70e-03 -0.039928 -0.068758 1.003 1.58e-03 0.00395    
384  1.16e-03 -9.48e-04 -0.000601  0.001252 1.025 5.24e-07 0.01651   *
385  1.85e-02 -1.96e-02  0.072458  0.121500 0.984 4.89e-03 0.00398    
386  1.44e-02 -1.53e-02 -0.016721 -0.033317 1.011 3.71e-04 0.00491    
387 -2.67e-02  4.03e-02 -0.030167  0.053223 1.023 9.46e-04 0.01655   *
388  1.04e-03 -1.10e-03  0.010657  0.017844 1.011 1.06e-04 0.00389    
389 -5.85e-02  6.19e-02 -0.031475 -0.077665 1.014 2.01e-03 0.01063    
390  3.08e-04 -3.26e-04  0.000601  0.001031 1.012 3.55e-07 0.00431    
391 -1.28e-02  1.36e-02 -0.041653 -0.070034 1.002 1.63e-03 0.00403    
392 -5.34e-04 -1.52e-03  0.004902 -0.006194 1.015 1.28e-05 0.00750    
393  2.81e-02 -2.98e-02 -0.037734 -0.072704 1.004 1.76e-03 0.00466    
394  5.51e-03 -5.83e-03 -0.031617 -0.054036 1.006 9.74e-04 0.00392    
395  2.36e-02 -2.50e-02 -0.018270 -0.041535 1.012 5.76e-04 0.00608    
396 -4.86e-02  5.15e-02  0.077420  0.144625 0.977 6.91e-03 0.00444   *
397  4.03e-03 -4.26e-03 -0.023118 -0.039511 1.009 5.21e-04 0.00392    
398 -6.37e-02  6.74e-02  0.024032  0.082145 1.015 2.25e-03 0.01186    
399 -5.54e-02  5.87e-02 -0.050427 -0.098458 1.001 3.23e-03 0.00601    
400 -5.23e-03  5.54e-03  0.030032  0.051327 1.006 8.79e-04 0.00392    

Problem 12

This problem involves simple linear regression without an intercept.

(a) Recall that the coefficient estimateˆ β for the linear regression of Y onto X without an intercept is given by (3.38). Under what circumstance is the coefficient estimate for the regression of X onto Y the same as the coefficient estimate for the regression of Y onto X?

The coefficient estimate for the regression of Y onto X is β̂ =∑ixiyi∑jx2j;

The coefficient estimate for the regression of X onto Y is β̂ ′=∑ixiyi∑jy2j.

The coefficients are the same iff ∑jx2j=∑jy2j.

(b) Generate an example in Python with n = 100 observations in which the coefficient estimate for the regression of X onto Y is different from the coefficient estimate for the regression of Y onto X.

set.seed(1)
x <- 1:100
sum(x^2)
[1] 338350
y <- 2 * x + rnorm(100, sd = 0.1)
sum(y^2)
[1] 1353606
fit.Y <- lm(y ~ x + 0)
fit.X <- lm(x ~ y + 0)
summary(fit.Y)

Call:
lm(formula = y ~ x + 0)

Residuals:
      Min        1Q    Median        3Q       Max 
-0.223590 -0.062560  0.004426  0.058507  0.230926 

Coefficients:
   Estimate Std. Error t value Pr(>|t|)    
x 2.0001514  0.0001548   12920   <2e-16 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 0.09005 on 99 degrees of freedom
Multiple R-squared:      1, Adjusted R-squared:      1 
F-statistic: 1.669e+08 on 1 and 99 DF,  p-value: < 2.2e-16
summary(fit.X)

Call:
lm(formula = x ~ y + 0)

Residuals:
      Min        1Q    Median        3Q       Max 
-0.115418 -0.029231 -0.002186  0.031322  0.111795 

Coefficients:
  Estimate Std. Error t value Pr(>|t|)    
y 5.00e-01   3.87e-05   12920   <2e-16 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 0.04502 on 99 degrees of freedom
Multiple R-squared:      1, Adjusted R-squared:      1 
F-statistic: 1.669e+08 on 1 and 99 DF,  p-value: < 2.2e-16

(c) Generate an example in Python with n = 100 observations in which the coefficient estimate for the regression of X onto Y is the same as the coefficient estimate for the regression of Y onto X.

x <- 1:100
sum(x^2)
[1] 338350
y <- 100:1
sum(y^2)
[1] 338350
fit.Y <- lm(y ~ x + 0)
fit.X <- lm(x ~ y + 0)
summary(fit.Y)

Call:
lm(formula = y ~ x + 0)

Residuals:
   Min     1Q Median     3Q    Max 
-49.75 -12.44  24.87  62.18  99.49 

Coefficients:
  Estimate Std. Error t value Pr(>|t|)    
x   0.5075     0.0866    5.86 6.09e-08 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 50.37 on 99 degrees of freedom
Multiple R-squared:  0.2575,    Adjusted R-squared:   0.25 
F-statistic: 34.34 on 1 and 99 DF,  p-value: 6.094e-08
summary(fit.X)

Call:
lm(formula = x ~ y + 0)

Residuals:
   Min     1Q Median     3Q    Max 
-49.75 -12.44  24.87  62.18  99.49 

Coefficients:
  Estimate Std. Error t value Pr(>|t|)    
y   0.5075     0.0866    5.86 6.09e-08 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 50.37 on 99 degrees of freedom
Multiple R-squared:  0.2575,    Adjusted R-squared:   0.25 
F-statistic: 34.34 on 1 and 99 DF,  p-value: 6.094e-08