library(datasets)
library(moments)
data("ChickWeight")

1.

  #a
  max_values <- sapply(airquality, max, na.rm = TRUE) 
  max_variable <- names(which.max(max_values)) 
  max_variable
## [1] "Solar.R"
  #b
  missing_vars <- names(airquality)[sapply(airquality, function(x) any(is.na(x)))] 
  airquality_clean <- na.omit(airquality)
  
  #c
  sk_values <- sapply(airquality_clean,skewness)
  max_sk_var <- names(which.max(sk_values))
  max_sk_var
## [1] "Ozone"
  #d
  hist(airquality_clean[[max_sk_var]],main = paste("Hist: ",max_sk_var))

  boxplot(airquality_clean[[max_sk_var]],main = paste("Boxplot: ",max_sk_var))  

e

Histogram ukazuje posun doľava alebo doprava. Zosikmenie premennej (skewness) môžeme na histograme identifikovať podľa toho, ako je rozdelenie hodnôt “naklonené”. Ak je distribúcia šikmá na pravú stranu (prítomnosť dlhšieho chvosta na pravej strane), hovoríme o pravej šikmosti (positívna šikmosť). Naopak, ak je rozdelenie šikmé na ľavú stranu (dlhší chvost na ľavej strane), ide o ľavú šikmosť (negatívna šikmosť). Ak je histogram symetrický, znamená to, že distribúcia je blízka normálnemu rozdeleniu a sklon je nula.

Na boxplote si môžete všimnúť asymetriu fúzov alebo umiestnenie mediánu.Na boxplote môžeme tiež pozorovať šikmosť. Ak sú “us” (whiskers) na jednej strane boxu dlhšie než na druhej strane, môže to naznačovať šikmosť. Ďalším indikátorom je pozícia mediány v rámci boxu: ak je mediána bližšie k spodnej alebo hornej časti boxu, môže to naznačovať sklon distribúcie.

2.

#a
sp_result <- sapply(ToothGrowth, function(x) if (is.numeric(x)) shapiro.test(x)$p.value else NA) 
normal_var <- names(sp_result)[which(sp_result > 0.1)]
normal_var
## [1] "len"
#b
t.test(ToothGrowth[[normal_var]],mu=20)
## 
##  One Sample t-test
## 
## data:  ToothGrowth[[normal_var]]
## t = -1.2017, df = 59, p-value = 0.2343
## alternative hypothesis: true mean is not equal to 20
## 95 percent confidence interval:
##  16.83731 20.78936
## sample estimates:
## mean of x 
##  18.81333
#c
t.test(ToothGrowth[[normal_var]] ~ ToothGrowth$supp, var.equal = TRUE)
## 
##  Two Sample t-test
## 
## data:  ToothGrowth[[normal_var]] by ToothGrowth$supp
## t = 1.9153, df = 58, p-value = 0.06039
## alternative hypothesis: true difference in means between group OJ and group VC is not equal to 0
## 95 percent confidence interval:
##  -0.1670064  7.5670064
## sample estimates:
## mean in group OJ mean in group VC 
##         20.66333         16.96333
t.test(ToothGrowth[[normal_var]] ~ ToothGrowth$supp, var.equal = TRUE, conf.level = 0.9)
## 
##  Two Sample t-test
## 
## data:  ToothGrowth[[normal_var]] by ToothGrowth$supp
## t = 1.9153, df = 58, p-value = 0.06039
## alternative hypothesis: true difference in means between group OJ and group VC is not equal to 0
## 90 percent confidence interval:
##  0.4708204 6.9291796
## sample estimates:
## mean in group OJ mean in group VC 
##         20.66333         16.96333

3.

#a
anova_model <- aov(weight ~ Diet, data = ChickWeight) 
summary(anova_model)
##              Df  Sum Sq Mean Sq F value   Pr(>F)    
## Diet          3  155863   51954   10.81 6.43e-07 ***
## Residuals   574 2758693    4806                     
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#c
TukeyHSD(anova_model)
##   Tukey multiple comparisons of means
##     95% family-wise confidence level
## 
## Fit: aov(formula = weight ~ Diet, data = ChickWeight)
## 
## $Diet
##          diff         lwr      upr     p adj
## 2-1 19.971212  -0.2998092 40.24223 0.0552271
## 3-1 40.304545  20.0335241 60.57557 0.0000025
## 4-1 32.617257  12.2353820 52.99913 0.0002501
## 3-2 20.333333  -2.7268370 43.39350 0.1058474
## 4-2 12.646045 -10.5116315 35.80372 0.4954239
## 4-3 -7.687288 -30.8449649 15.47039 0.8277810

4.

#a
cor_matrix <- cor(airquality_clean,use="complete.obs")
ozone_cor <- cor_matrix["Ozone",]
strngst_pos <- names(which.max(ozone_cor[ozone_cor<1]))
strngst_neg <- names(which.min(ozone_cor))
strngst_pos
## [1] "Temp"
strngst_neg
## [1] "Wind"
#b
spearman_cor <- cor(airquality_clean,method = "spearman",use = "complete.obs")
kendall_cor <- cor(airquality_clean,method = "kendall",use = "complete.obs")

spearman_cor["Ozone",]
##       Ozone     Solar.R        Wind        Temp       Month         Day 
##  1.00000000  0.34818647 -0.60513642  0.77293193  0.11669011 -0.03504654
kendall_cor["Ozone",]
##       Ozone     Solar.R        Wind        Temp       Month         Day 
##  1.00000000  0.24031942 -0.44045944  0.58614712  0.08859401 -0.03041526
#c
plot(airquality_clean$Ozone,airquality_clean[[strngst_pos]],main = "Ozone vs strongest Positive")

plot(airquality_clean$Ozone,airquality_clean[[strngst_neg]],main = "Ozone vs strongest Negative")

5.

#a
linear_model <- lm(weight ~ Time + Diet, data = ChickWeight) 
summary(linear_model)$adj.r.squared
## [1] 0.7435224
summary(linear_model)
## 
## Call:
## lm(formula = weight ~ Time + Diet, data = ChickWeight)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -136.851  -17.151   -2.595   15.033  141.816 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  10.9244     3.3607   3.251  0.00122 ** 
## Time          8.7505     0.2218  39.451  < 2e-16 ***
## Diet2        16.1661     4.0858   3.957 8.56e-05 ***
## Diet3        36.4994     4.0858   8.933  < 2e-16 ***
## Diet4        30.2335     4.1075   7.361 6.39e-13 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 35.99 on 573 degrees of freedom
## Multiple R-squared:  0.7453, Adjusted R-squared:  0.7435 
## F-statistic: 419.2 on 4 and 573 DF,  p-value: < 2.2e-16
#b
full_model <- lm(weight ~ . , data = ChickWeight) 
summary(full_model)$adj.r.squared 
## [1] 0.8416462
summary(full_model)
## 
## Call:
## lm(formula = weight ~ ., data = ChickWeight)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -80.128 -15.976  -2.476  13.844  91.955 
## 
## Coefficients: (3 not defined because of singularities)
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  27.8983     2.2157  12.591  < 2e-16 ***
## Time          8.7152     0.1759  49.538  < 2e-16 ***
## Chick.L     130.2672     9.5424  13.651  < 2e-16 ***
## Chick.Q     -24.9790    10.1028  -2.472 0.013732 *  
## Chick.C     -16.2937    10.4180  -1.564 0.118422    
## Chick^4      16.8300    10.5032   1.602 0.109674    
## Chick^5     -11.8874    10.4181  -1.141 0.254373    
## Chick^6      62.0273    10.2441   6.055 2.67e-09 ***
## Chick^7      -5.7763    10.0555  -0.574 0.565913    
## Chick^8      -2.1871     9.8366  -0.222 0.824137    
## Chick^9      -2.5741     9.5743  -0.269 0.788145    
## Chick^10    -15.8198     9.3250  -1.696 0.090382 .  
## Chick^11    -29.2864     9.0988  -3.219 0.001367 ** 
## Chick^12     12.6115     8.8899   1.419 0.156599    
## Chick^13     45.5732     8.7345   5.218 2.61e-07 ***
## Chick^14      8.4847     8.6499   0.981 0.327089    
## Chick^15    -36.7921     8.5910  -4.283 2.19e-05 ***
## Chick^16    -18.5430     8.5389  -2.172 0.030332 *  
## Chick^17     13.8154     8.5068   1.624 0.104966    
## Chick^18     19.2098     8.4673   2.269 0.023690 *  
## Chick^19    -15.1139     8.3971  -1.800 0.072450 .  
## Chick^20     19.1073     8.3290   2.294 0.022178 *  
## Chick^21     10.3924     8.3016   1.252 0.211177    
## Chick^22    -13.8848     8.2768  -1.678 0.094028 .  
## Chick^23     -2.6091     8.2224  -0.317 0.751133    
## Chick^24      3.7279     8.1876   0.455 0.649070    
## Chick^25    -30.7405     8.2072  -3.746 0.000200 ***
## Chick^26     22.9762     8.2255   2.793 0.005407 ** 
## Chick^27     37.2504     8.1981   4.544 6.86e-06 ***
## Chick^28     11.6756     8.1679   1.429 0.153467    
## Chick^29    -15.8480     8.1893  -1.935 0.053501 .  
## Chick^30     -9.6065     8.2243  -1.168 0.243313    
## Chick^31      2.6487     8.2253   0.322 0.747567    
## Chick^32     15.8318     8.1691   1.938 0.053157 .  
## Chick^33     -4.2143     8.1816  -0.515 0.606701    
## Chick^34     -8.3473     8.1762  -1.021 0.307759    
## Chick^35      0.6771     8.1644   0.083 0.933933    
## Chick^36    -17.3659     8.1675  -2.126 0.033948 *  
## Chick^37     -2.6001     8.1705  -0.318 0.750436    
## Chick^38    -15.5406     8.1727  -1.902 0.057778 .  
## Chick^39     -2.8088     8.2396  -0.341 0.733324    
## Chick^40     39.4063     8.2667   4.767 2.42e-06 ***
## Chick^41    -15.4934     8.2493  -1.878 0.060914 .  
## Chick^42    -27.7127     8.1962  -3.381 0.000775 ***
## Chick^43    -32.3320     8.1715  -3.957 8.64e-05 ***
## Chick^44     -9.6068     8.1724  -1.176 0.240318    
## Chick^45    -12.8100     8.1665  -1.569 0.117338    
## Chick^46     21.7381     8.1646   2.662 0.007994 ** 
## Chick^47      6.3382     8.1950   0.773 0.439623    
## Chick^48     16.3989     8.1667   2.008 0.045152 *  
## Chick^49    -25.3853     8.1647  -3.109 0.001978 ** 
## Diet2             NA         NA      NA       NA    
## Diet3             NA         NA      NA       NA    
## Diet4             NA         NA      NA       NA    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 28.28 on 527 degrees of freedom
## Multiple R-squared:  0.8554, Adjusted R-squared:  0.8416 
## F-statistic: 62.33 on 50 and 527 DF,  p-value: < 2.2e-16
#c
AIC(linear_model,full_model)
##              df      AIC
## linear_model  6 5789.607
## full_model   52 5554.520
BIC(linear_model,full_model)
##              df      BIC
## linear_model  6 5815.765
## full_model   52 5781.218
#d


linear_model
## 
## Call:
## lm(formula = weight ~ Time + Diet, data = ChickWeight)
## 
## Coefficients:
## (Intercept)         Time        Diet2        Diet3        Diet4  
##       10.92         8.75        16.17        36.50        30.23
full_model
## 
## Call:
## lm(formula = weight ~ ., data = ChickWeight)
## 
## Coefficients:
## (Intercept)         Time      Chick.L      Chick.Q      Chick.C      Chick^4  
##     27.8983       8.7152     130.2672     -24.9790     -16.2937      16.8300  
##     Chick^5      Chick^6      Chick^7      Chick^8      Chick^9     Chick^10  
##    -11.8874      62.0273      -5.7763      -2.1871      -2.5741     -15.8198  
##    Chick^11     Chick^12     Chick^13     Chick^14     Chick^15     Chick^16  
##    -29.2864      12.6115      45.5732       8.4847     -36.7921     -18.5430  
##    Chick^17     Chick^18     Chick^19     Chick^20     Chick^21     Chick^22  
##     13.8154      19.2098     -15.1139      19.1073      10.3924     -13.8848  
##    Chick^23     Chick^24     Chick^25     Chick^26     Chick^27     Chick^28  
##     -2.6091       3.7279     -30.7405      22.9762      37.2504      11.6756  
##    Chick^29     Chick^30     Chick^31     Chick^32     Chick^33     Chick^34  
##    -15.8480      -9.6065       2.6487      15.8318      -4.2143      -8.3473  
##    Chick^35     Chick^36     Chick^37     Chick^38     Chick^39     Chick^40  
##      0.6771     -17.3659      -2.6001     -15.5406      -2.8088      39.4063  
##    Chick^41     Chick^42     Chick^43     Chick^44     Chick^45     Chick^46  
##    -15.4934     -27.7127     -32.3320      -9.6068     -12.8100      21.7381  
##    Chick^47     Chick^48     Chick^49        Diet2        Diet3        Diet4  
##      6.3382      16.3989     -25.3853           NA           NA           NA
#best_model <- ifelse(AIC(linear_model) < AIC(full_model), linear_model, full_model) 
#best_model
#residuals(best_model)
#shapiro.test(residuals(best_model)) 
#acf(residuals(best_model))


best_model <- linear_model
best_model
## 
## Call:
## lm(formula = weight ~ Time + Diet, data = ChickWeight)
## 
## Coefficients:
## (Intercept)         Time        Diet2        Diet3        Diet4  
##       10.92         8.75        16.17        36.50        30.23
residuals(best_model)
##             1             2             3             4             5 
##   31.07560890   22.57462541   13.07364193    0.57265844   -4.92832504 
##             6             7             8             9            10 
##   -5.42930852   -9.93029201   -8.43127549   -1.93225898    2.56675754 
##            11            12            13            14            15 
##   13.06577405   10.31528231   29.07560890   20.57462541   12.07364193 
##            16            17            18            19            20 
##    8.57265844    3.07167496    4.57069148    6.06970799    4.56872451 
##            21            22            23            24            25 
##   11.06774102   18.56675754   23.06577405   20.31528231   32.07560890 
##            26            27            28            29            30 
##   10.57462541    9.07364193    3.57265844    3.07167496    0.57069148 
##            31            32            33            34            35 
##   -0.93029201    4.56872451   12.06774102   18.56675754   12.06577405 
##            36            37            38            39            40 
##    7.31528231   31.07560890   20.57462541   10.07364193    3.57265844 
##            41            42            43            44            45 
##   -6.92832504  -11.42930852  -13.93029201  -25.43127549  -14.93225898 
##            46            47            48            49            50 
##  -14.43324246  -25.93422595  -37.68471769   30.07560890   13.57462541 
##            51            52            53            54            55 
##    2.07364193   -3.42734156   -1.92832504    7.57069148   25.06970799 
##            56            57            58            59            60 
##   30.56872451   46.06774102   30.56675754   34.06577405   28.31528231 
##            61            62            63            64            65 
##   30.07560890   20.57462541   13.07364193   10.57265844   16.07167496 
##            66            67            68            69            70 
##   25.57069148   25.06970799   14.56872451    4.06774102   -8.43324246 
##            71            72            73            74            75 
##  -25.93422595  -37.68471769   30.07560890   20.57462541   11.07364193 
##            76            77            78            79            80 
##    7.57265844    8.07167496   13.57069148   30.06970799   40.56872451 
##            81            82            83            84            85 
##   67.06774102   81.56675754  102.06577405  110.31528231   31.07560890 
##            86            87            88            89            90 
##   21.57462541   15.07364193    7.57265844    3.07167496   -5.42930852 
##            91            92            93            94            95 
##   -5.93029201  -17.43127549  -24.93225898  -34.43324246  -60.93422595 
##            96            97            98            99           100 
##   31.07560890   22.57462541   13.07364193    4.57265844    4.07167496 
##           101           102           103           104           105 
##   -2.42930852  -25.93029201  -41.43127549  -57.93225898  -68.43324246 
##           106           107           108           109           110 
##  -85.93422595  -96.68471769   30.07560890   15.57462541    6.07364193 
##           111           112           113           114           115 
##   -0.42734156   -6.92832504  -17.42930852  -26.93029201  -37.43127549 
##           116           117           118           119           120 
##  -49.93225898  -56.43324246  -65.93422595  -70.68471769   32.07560890 
##           121           122           123           124           125 
##   22.57462541   17.07364193   20.57265844   31.07167496   40.57069148 
##           126           127           128           129           130 
##   52.06970799   43.56872451   31.06774102   15.56675754   -4.93422595 
##           131           132           133           134           135 
##  -19.68471769   30.07560890   20.57462541   10.07364193   -1.42734156 
##           136           137           138           139           140 
##   -8.92832504  -10.42930852    3.06970799    1.56872451   11.06774102 
##           141           142           143           144           145 
##   16.56675754    9.06577405   10.31528231   30.07560890   19.57462541 
##           146           147           148           149           150 
##    7.07364193   -3.42734156  -15.92832504  -31.42930852  -44.93029201 
##           151           152           153           154           155 
##  -63.43127549  -79.93225898  -87.43324246  -94.93422595  -98.68471769 
##           156           157           158           159           160 
##   30.07560890   20.57462541   16.07364193   15.57265844   20.07167496 
##           161           162           163           164           165 
##   29.57069148   48.06970799   58.56872451   76.06774102   79.56675754 
##           166           167           168           169           170 
##   73.06577405   71.31528231   30.07560890   20.57462541   10.07364193 
##           171           172           173           174           175 
##    0.57265844  -12.92832504  -30.42930852  -48.93029201  -65.43127549 
##           176           177           178           179           180 
##   30.07560890   16.57462541    3.07364193  -12.42734156  -23.92832504 
##           181           182           183           184           185 
##  -47.42930852  -61.93029201   31.07560890   22.57462541   15.07364193 
##           186           187           188           189           190 
##    8.57265844    2.07167496   -9.42930852  -17.93029201  -30.43127549 
##           191           192           193           194           195 
##  -37.93225898  -45.43324246  -52.93422595  -52.68471769   28.07560890 
##           196           197           198           199           200 
##    6.57462541   32.07560890   19.57462541    9.07364193   -1.42734156 
##           201           202           203           204           205 
##  -15.92832504  -27.42930852  -33.93029201  -45.43127549  -44.93225898 
##           206           207           208           209           210 
##  -48.43324246  -41.93422595  -37.68471769   30.07560890   18.57462541 
##           211           212           213           214           215 
##    8.07364193   -5.42734156  -15.92832504  -25.42930852  -38.93029201 
##           216           217           218           219           220 
##  -44.43127549  -52.93225898  -61.43324246  -70.93422595  -77.68471769 
##           221           222           223           224           225 
##   12.90953485    5.40855137   -0.09243212    6.40658440   27.90560091 
##           226           227           228           229           230 
##   48.40461743   84.90363395   90.40265046  107.90166698  122.40068349 
##           231           232           233           234           235 
##  115.89970001  120.14920827   13.90953485   10.40855137    1.90756788 
##           236           237           238           239           240 
##   -2.59341560   -7.09439909  -19.59538257  -24.09636605  -38.59734954 
##           241           242           243           244           245 
##  -36.09833302  -36.59931651  -38.10029999  -43.85079173   15.90953485 
##           246           247           248           249           250 
##    7.40855137   -1.09243212   -6.59341560   -7.09439909  -11.59538257 
##           251           252           253           254           255 
##   -5.09636605  -14.59734954  -22.09833302  -21.59931651  -32.10029999 
##           256           257           258           259           260 
##  -35.85079173   14.90953485    7.40855137   -4.09243212   -5.59341560 
##           261           262           263           264           265 
##  -31.09439909  -46.59538257  -62.09636605  -78.59734954  -95.09833302 
##           266           267           268           269           270 
## -112.59931651 -126.10029999 -136.85079173   12.90953485    4.40855137 
##           271           272           273           274           275 
##   -0.09243212   -1.59341560    4.90560091    9.40461743   13.90363395 
##           276           277           278           279           280 
##   14.40265046   29.90166698   46.40068349   56.89970001   54.14920827 
##           281           282           283           284           285 
##   14.90953485    3.40855137   -5.09243212   -5.59341560   -4.09439909 
##           286           287           288           289           290 
##   -0.59538257    3.90363395   -2.59734954    1.90166698   20.40068349 
##           291           292           293           294           295 
##   33.89970001   40.14920827   11.90953485    1.40855137   -4.09243212 
##           296           297           298           299           300 
##   -6.59341560  -10.09439909  -14.59538257  -17.09636605  -26.59734954 
##           301           302           303           304           305 
##  -23.09833302  -21.59931651  -17.10029999  -18.85079173   11.90953485 
##           306           307           308           309           310 
##    1.40855137   -4.09243212   -6.59341560   -5.09439909   -0.59538257 
##           311           312           313           314           315 
##   12.90363395    6.40265046   16.90166698   22.40068349    9.89970001 
##           316           317           318           319           320 
##   22.14920827   11.90953485    3.40855137   -3.09243212   -5.59341560 
##           321           322           323           324           325 
##  -10.09439909   -8.59538257    1.90363395    0.40265046   19.90166698 
##           326           327           328           329           330 
##   45.40068349   76.89970001   98.14920827   14.90953485    3.40855137 
##           331           332           333           334           335 
##   -3.09243212   -7.59341560  -12.09439909  -16.59538257  -17.09636605 
##           336           337           338           339           340 
##  -27.59734954  -24.09833302  -33.59931651  -45.10029999  -60.85079173 
##           341           342           343           344           345 
##   -5.42379848  -11.92478197  -20.42576545  -26.92674893  -32.42773242 
##           346           347           348           349           350 
##  -32.92871590  -29.42969939  -31.93068287  -17.43166636   -0.93264984 
##           351           352           353           354           355 
##   12.56636667   24.81587493   -6.42379848  -15.92478197  -17.42576545 
##           356           357           358           359           360 
##  -17.92674893  -10.42773242   -5.92871590    6.57030061    9.06931713 
##           361           362           363           364           365 
##   33.56833364   58.06735016   68.56636667   73.81587493   -8.42379848 
##           366           367           368           369           370 
##  -14.92478197  -19.42576545  -22.92674893  -21.42773242  -23.92871590 
##           371           372           373           374           375 
##  -15.42969939  -25.93068287  -36.43166636  -58.93264984  -66.43363333 
##           376           377           378           379           380 
##  -84.18412507   -6.42379848  -15.92478197  -19.42576545  -14.92674893 
##           381           382           383           384           385 
##  -10.42773242   -0.92871590   11.57030061   16.06931713   47.56833364 
##           386           387           388           389           390 
##   89.06735016  104.56636667  109.81587493   -6.42379848  -11.92478197 
##           391           392           393           394           395 
##  -18.42576545  -12.92674893    5.57226758   23.07128410   48.57030061 
##           396           397           398           399           400 
##   68.06931713   99.56833364  127.06735016  138.56636667  141.81587493 
##           401           402           403           404           405 
##   -8.42379848  -16.92478197  -21.42576545  -23.92674893  -19.42773242 
##           406           407           408           409           410 
##  -18.92871590   -7.42969939   -3.93068287   10.56833364   22.06735016 
##           411           412           413           414           415 
##    2.56636667  -11.18412507   -6.42379848  -16.92478197  -26.42576545 
##           416           417           418           419           420 
##  -31.92674893  -37.42773242  -51.92871590  -49.42969939  -57.93068287 
##           421           422           423           424           425 
##  -52.43166636  -47.93264984  -53.43363333  -53.18412507   -6.42379848 
##           426           427           428           429           430 
##  -15.92478197  -21.42576545  -25.92674893  -19.42773242  -25.92871590 
##           431           432           433           434           435 
##  -24.42969939  -15.93068287    4.56833364   27.06735016   57.56636667 
##           436           437           438           439           440 
##   58.81587493   -5.42379848  -14.92478197  -21.42576545  -21.92674893 
##           441           442           443           444           445 
##  -28.42773242  -25.92871590  -22.42969939  -23.93068287  -17.43166636 
##           446           447           448           449           450 
##    9.06735016   27.56636667   40.81587493   -6.42379848   -9.92478197 
##           451           452           453           454           455 
##  -16.42576545  -20.92674893  -16.42773242  -14.92871590    1.57030061 
##           456           457           458           459           460 
##   12.06931713   27.56833364   57.06735016   72.56636667   89.81587493 
##           461           462           463           464           465 
##    0.84215272   -7.65883076  -10.15981425   -8.66079773   -8.16178122 
##           466           467           468           469           470 
##   -4.66276470    8.83625181  -10.66473167   -6.16571516  -14.66669864 
##           471           472           473           474           475 
##  -17.16768213  -20.91817387    0.84215272   -9.65883076  -13.15981425 
##           476           477           478           479           480 
##   -9.66079773   -8.16178122   -2.66276470   13.83625181   10.33526833 
##           481           482           483           484           485 
##   22.83428484   35.33330136   52.83231787   56.08182613    0.84215272 
##           486           487           488           489           490 
##   -3.65883076   -7.15981425    2.33920227   19.83821878   28.33723530 
##           491           492           493           494           495 
##   37.83625181   24.33526833   15.83428484   -0.66669864  -17.16768213 
##           496           497           498           499           500 
##  -24.91817387    0.84215272   -7.65883076  -11.15981425   -7.66079773 
##           501           502           503           504           505 
##   -8.16178122  -10.66276470  -19.16374819  -25.66473167  -36.16571516 
##           506           507           508           509           510 
##  -52.66669864   -0.15784728   -8.65883076  -15.15981425  -15.66079773 
##           511           512           513           514           515 
##  -13.16178122  -11.66276470  -11.16374819  -22.66473167  -34.16571516 
##           516           517           518           519           520 
##  -24.66669864  -19.16768213  -28.91817387   -1.15784728   -6.65883076 
##           521           522           523           524           525 
##  -14.15981425  -11.66079773  -10.16178122   -8.66276470   -2.16374819 
##           526           527           528           529           530 
##   -7.66473167   -8.16571516   11.33330136   14.83231787   13.08182613 
##           531           532           533           534           535 
##   -0.15784728   -5.65883076  -10.15981425  -14.66079773  -11.16178122 
##           536           537           538           539           540 
##   -5.66276470    1.83625181   -6.66473167  -13.16571516  -13.66669864 
##           541           542           543           544           545 
##   -6.16768213  -19.91817387   -2.15784728   -8.65883076  -14.15981425 
##           546           547           548           549           550 
##  -13.66079773   -7.16178122   -3.66276470    7.83625181    6.33526833 
##           551           552           553           554           555 
##   40.83428484   62.33330136   86.83231787   97.08182613   -1.15784728 
##           556           557           558           559           560 
##   -5.65883076  -12.15981425   -8.66079773   -3.16178122   -0.66276470 
##           561           562           563           564           565 
##    5.83625181    2.33526833    2.83428484    4.33330136   16.83231787 
##           566           567           568           569           570 
##   12.08182613   -0.15784728   -4.65883076   -9.15981425   -9.66079773 
##           571           572           573           574           575 
##   -6.16178122   -6.66276470    8.83625181   11.33526833   23.83428484 
##           576           577           578 
##   35.33330136   47.83231787   39.08182613
shapiro.test(residuals(best_model)) 
## 
##  Shapiro-Wilk normality test
## 
## data:  residuals(best_model)
## W = 0.94571, p-value = 1.032e-13
acf(residuals(best_model))