library(tidyverse)
library(olsrr)
library(car)
library(gvlma)
options(scipen=8)

data <- read.csv("https://raw.githubusercontent.com/mandiemannz/Data-605---Spring-2019/master/who.csv?token=AF5OF3NJT3MYN457JBJIOJS4YZJDI", header = T)

data
##                                       Country LifeExp InfantSurvival
## 1                                 Afghanistan      42          0.835
## 2                                     Albania      71          0.985
## 3                                     Algeria      71          0.967
## 4                                     Andorra      82          0.997
## 5                                      Angola      41          0.846
## 6                         Antigua and Barbuda      73          0.990
## 7                                   Argentina      75          0.986
## 8                                     Armenia      69          0.979
## 9                                   Australia      82          0.995
## 10                                    Austria      80          0.996
## 11                                 Azerbaijan      64          0.927
## 12                                    Bahamas      74          0.987
## 13                                    Bahrain      75          0.991
## 14                                 Bangladesh      63          0.948
## 15                                   Barbados      75          0.989
## 16                                    Belarus      69          0.994
## 17                                    Belgium      79          0.996
## 18                                     Belize      69          0.986
## 19                                      Benin      55          0.912
## 20                                     Bhutan      64          0.937
## 21                                    Bolivia      66          0.950
## 22                     Bosnia and Herzegovina      75          0.987
## 23                                   Botswana      52          0.910
## 24                                     Brazil      72          0.981
## 25                          Brunei Darussalam      77          0.992
## 26                                   Bulgaria      73          0.990
## 27                               Burkina Faso      47          0.878
## 28                                    Burundi      49          0.891
## 29                                   Cambodia      62          0.935
## 30                                   Cameroon      51          0.913
## 31                                     Canada      81          0.995
## 32                                 Cape Verde      70          0.975
## 33                   Central African Republic      48          0.886
## 34                                       Chad      46          0.876
## 35                                      Chile      78          0.992
## 36                                      China      73          0.980
## 37                                   Colombia      74          0.983
## 38                                    Comoros      65          0.949
## 39                                      Congo      54          0.921
## 40                               Cook Islands      73          0.984
## 41                                 Costa Rica      78          0.989
## 42                           C\xf4te d'Ivoire      53          0.910
## 43                                    Croatia      76          0.995
## 44                                       Cuba      78          0.995
## 45                                     Cyprus      80          0.997
## 46                             Czech Republic      77          0.997
## 47           Democratic Republic of the Congo      47          0.871
## 48                                    Denmark      79          0.997
## 49                                   Djibouti      56          0.914
## 50                                   Dominica      74          0.987
## 51                         Dominican Republic      70          0.975
## 52                                    Ecuador      73          0.979
## 53                                      Egypt      68          0.971
## 54                                El Salvador      71          0.978
## 55                          Equatorial Guinea      46          0.876
## 56                                    Eritrea      63          0.952
## 57                                    Estonia      73          0.995
## 58                                   Ethiopia      56          0.923
## 59                                       Fiji      69          0.984
## 60                                    Finland      79          0.997
## 61                                     France      81          0.996
## 62                                      Gabon      58          0.940
## 63                                     Gambia      59          0.916
## 64                                    Georgia      70          0.972
## 65                                    Germany      80          0.996
## 66                                      Ghana      57          0.924
## 67                                     Greece      80          0.996
## 68                                    Grenada      68          0.983
## 69                                  Guatemala      68          0.969
## 70                                     Guinea      53          0.902
## 71                              Guinea-Bissau      48          0.881
## 72                                     Guyana      64          0.954
## 73                                      Haiti      61          0.940
## 74                                   Honduras      70          0.977
## 75                                    Hungary      73          0.994
## 76                                    Iceland      81          0.998
## 77                                      India      63          0.943
## 78                                  Indonesia      68          0.974
## 79                 Iran (Islamic Republic of)      71          0.970
## 80                                       Iraq      56          0.963
## 81                                    Ireland      80          0.996
## 82                                     Israel      81          0.996
## 83                                      Italy      81          0.997
## 84                                    Jamaica      72          0.974
## 85                                      Japan      83          0.997
## 86                                     Jordan      71          0.979
## 87                                 Kazakhstan      64          0.974
## 88                                      Kenya      53          0.921
## 89                                   Kiribati      65          0.953
## 90                                     Kuwait      78          0.991
## 91                                 Kyrgyzstan      66          0.964
## 92           Lao People's Democratic Republic      60          0.941
## 93                                     Latvia      71          0.992
## 94                                    Lebanon      70          0.973
## 95                                    Lesotho      42          0.898
## 96                                    Liberia      44          0.843
## 97                     Libyan Arab Jamahiriya      72          0.983
## 98                                  Lithuania      71          0.993
## 99                                 Luxembourg      80          0.997
## 100                                Madagascar      59          0.928
## 101                                    Malawi      50          0.924
## 102                                  Malaysia      72          0.990
## 103                                  Maldives      72          0.974
## 104                                      Mali      46          0.881
## 105                                     Malta      79          0.995
## 106                          Marshall Islands      63          0.950
## 107                                Mauritania      58          0.922
## 108                                 Mauritius      73          0.988
## 109                                    Mexico      74          0.971
## 110          Micronesia (Federated States of)      69          0.967
## 111                                    Monaco      82          0.997
## 112                                  Mongolia      66          0.965
## 113                                Montenegro      74          0.991
## 114                                   Morocco      72          0.966
## 115                                Mozambique      50          0.904
## 116                                   Namibia      61          0.955
## 117                                     Nauru      61          0.975
## 118                                     Nepal      62          0.954
## 119                               Netherlands      80          0.996
## 120                               New Zealand      80          0.995
## 121                                 Nicaragua      71          0.971
## 122                                     Niger      42          0.852
## 123                                   Nigeria      48          0.901
## 124                                      Niue      70          0.966
## 125                                    Norway      80          0.997
## 126                                      Oman      74          0.990
## 127                                  Pakistan      63          0.922
## 128                                     Palau      69          0.990
## 129                                    Panama      76          0.982
## 130                          Papua New Guinea      62          0.946
## 131                                  Paraguay      75          0.981
## 132                                      Peru      73          0.979
## 133                               Philippines      68          0.976
## 134                                    Poland      75          0.994
## 135                                  Portugal      79          0.997
## 136                                     Qatar      77          0.991
## 137                         Republic of Korea      79          0.995
## 138                       Republic of Moldova      68          0.984
## 139                                   Romania      73          0.986
## 140                        Russian Federation      66          0.990
## 141                                    Rwanda      52          0.903
## 142                     Saint Kitts and Nevis      71          0.983
## 143                               Saint Lucia      75          0.988
## 144          Saint Vincent and the Grenadines      70          0.983
## 145                                     Samoa      68          0.977
## 146                                San Marino      82          0.997
## 147                     Sao Tome and Principe      61          0.937
## 148                              Saudi Arabia      70          0.979
## 149                                   Senegal      59          0.940
## 150                                    Serbia      73          0.993
## 151                                Seychelles      72          0.988
## 152                              Sierra Leone      40          0.841
## 153                                 Singapore      80          0.997
## 154                                  Slovakia      74          0.993
## 155                                  Slovenia      78          0.997
## 156                           Solomon Islands      67          0.945
## 157                              South Africa      51          0.944
## 158                                     Spain      81          0.996
## 159                                 Sri Lanka      72          0.989
## 160                                     Sudan      60          0.938
## 161                                  Suriname      68          0.971
## 162                                 Swaziland      42          0.888
## 163                                    Sweden      81          0.997
## 164                               Switzerland      82          0.996
## 165                      Syrian Arab Republic      72          0.988
## 166                                Tajikistan      64          0.944
## 167                                  Thailand      72          0.993
## 168 The former Yugoslav Republic of Macedonia      73          0.985
## 169                               Timor-Leste      66          0.953
## 170                                      Togo      57          0.931
## 171                                     Tonga      71          0.980
## 172                       Trinidad and Tobago      69          0.967
## 173                                   Tunisia      72          0.981
## 174                                    Turkey      73          0.976
## 175                              Turkmenistan      63          0.955
## 176                                    Tuvalu      65          0.969
## 177                                    Uganda      50          0.922
## 178                                   Ukraine      67          0.980
## 179                      United Arab Emirates      78          0.992
## 180                            United Kingdom      79          0.995
## 181               United Republic of Tanzania      50          0.926
## 182                  United States of America      78          0.993
## 183                                   Uruguay      75          0.987
## 184                                Uzbekistan      68          0.962
## 185                                   Vanuatu      69          0.970
## 186        Venezuela (Bolivarian Republic of)      74          0.982
## 187                                  Viet Nam      72          0.985
## 188                                     Yemen      61          0.925
## 189                                    Zambia      43          0.898
## 190                                  Zimbabwe      43          0.945
##     Under5Survival  TBFree      PropMD      PropRN PersExp GovtExp TotExp
## 1            0.743 0.99769 0.000228841 0.000572294      20      92    112
## 2            0.983 0.99974 0.001143127 0.004614439     169    3128   3297
## 3            0.962 0.99944 0.001060478 0.002091362     108    5184   5292
## 4            0.996 0.99983 0.003297297 0.003500000    2589  169725 172314
## 5            0.740 0.99656 0.000070400 0.001146162      36    1620   1656
## 6            0.989 0.99991 0.000142857 0.002773810     503   12543  13046
## 7            0.983 0.99952 0.002780191 0.000741044     484   19170  19654
## 8            0.976 0.99920 0.003698671 0.004918937      88    1856   1944
## 9            0.994 0.99993 0.002331953 0.009149391    3181  187616 190797
## 10           0.996 0.99990 0.003610904 0.006458749    3788  189354 193142
## 11           0.911 0.99913 0.003660005 0.008477873      62     780    842
## 12           0.986 0.99960 0.000954128 0.004045872    1224   55783  57007
## 13           0.990 0.99955 0.002679296 0.005967524     710   45784  46494
## 14           0.931 0.99609 0.000274894 0.000253034      12      75     87
## 15           0.988 0.99989 0.001098976 0.003372014     725   24433  25158
## 16           0.992 0.99929 0.004758674 0.012457093     204   11315  11519
## 17           0.995 0.99989 0.004230489 0.014079195    3451  239105 242556
## 18           0.984 0.99944 0.000890071 0.001074468     198    5376   5574
## 19           0.852 0.99865 0.000035500 0.000660845      28     600    628
## 20           0.930 0.99904 0.000080100 0.001124807      52     407    459
## 21           0.939 0.99734 0.001104233 0.001934039      71    2860   2931
## 22           0.985 0.99943 0.001411105 0.004669384     243    6578   6821
## 23           0.876 0.99546 0.000384822 0.002558127     431   19604  20035
## 24           0.980 0.99945 0.001046640 0.003481410     371   13940  14311
## 25           0.991 0.99901 0.001047120 0.005549738     519   30562  31081
## 26           0.988 0.99959 0.000253477 0.004553230     272   11550  11822
## 27           0.796 0.99524 0.000049300 0.000456647      27     304    331
## 28           0.819 0.99286 0.000024500 0.000164933       3      10     13
## 29           0.918 0.99335 0.000144185 0.000783616      29     140    169
## 30           0.851 0.99763 0.000171884 0.001432847      49     784    833
## 31           0.994 0.99996 0.001912607 0.010044633    3430  192800 196230
## 32           0.966 0.99676 0.000445087 0.000789981     114    5394   5508
## 33           0.826 0.99472 0.000077600 0.000378195      13     190    203
## 34           0.791 0.99430 0.000033000 0.000238728      22     234    256
## 35           0.991 0.99984 0.001047677 0.000607349     397   17952  18349
## 36           0.976 0.99799 0.001402082 0.000979500      81    1302   1383
## 37           0.979 0.99941 0.001289806 0.000525484     201   12410  12611
## 38           0.932 0.99914 0.000140587 0.000718826      14     304    318
## 39           0.874 0.99434 0.000204934 0.000995392      31     915    946
## 40           0.981 0.99976 0.001428571 0.005714286     466   27264  27730
## 41           0.988 0.99983 0.001182996 0.000830416     327   15376  15703
## 42           0.873 0.99253 0.000110024 0.000538226      34     315    349
## 43           0.994 0.99936 0.002469271 0.005459175     651   30210  30861
## 44           0.993 0.99990 0.005908139 0.007444750     310   21075  21385
## 45           0.996 0.99994 0.033228132 0.003972813    1350   39399  40749
## 46           0.996 0.99990 0.003591618 0.008942978     868   56137  57005
## 47           0.795 0.99355 0.000096100 0.000474721       5      66     71
## 48           0.996 0.99993 0.003551934 0.009958195    4350  314588 318938
## 49           0.870 0.98700 0.000170940 0.000361416      61    4002   4063
## 50           0.985 0.99984 0.000558824 0.004661765     288   13206  13494
## 51           0.971 0.99882 0.001629745 0.001596672     197    4148   4345
## 52           0.976 0.99805 0.001388805 0.001559309     147    3717   3864
## 53           0.965 0.99969 0.002425640 0.003367945      78    1290   1368
## 54           0.975 0.99936 0.001173913 0.000754658     177    5700   5877
## 55           0.794 0.99596 0.000308468 0.000546371     211    6474   6685
## 56           0.926 0.99782 0.000045800 0.000533887       8      80     88
## 57           0.994 0.99960 0.003294030 0.006900746     516   27393  27909
## 58           0.877 0.99359 0.000023900 0.000191851       6      64     70
## 59           0.982 0.99970 0.000456182 0.001992797     148    5355   5503
## 60           0.997 0.99996 0.003299183 0.008920357    2824  133956 136780
## 61           0.995 0.99989 0.003379700 0.007924442    3819  234850 238669
## 62           0.909 0.99572 0.000301297 0.005170099     276   17220  17496
## 63           0.886 0.99577 0.000093800 0.001131088      15     550    565
## 64           0.968 0.99916 0.004646289 0.004031356     123    1248   1371
## 65           0.995 0.99995 0.003441718 0.008010552    3628  209250 212878
## 66           0.880 0.99621 0.000140821 0.000856528      30     490    520
## 67           0.996 0.99984 0.004994696 0.003596152    2580   65195  67775
## 68           0.980 0.99992 0.000754717 0.003075472     342    6944   7286
## 69           0.959 0.99897 0.000764832 0.003452759     132    2400   2532
## 70           0.839 0.99534 0.000107505 0.000480122      21      66     87
## 71           0.800 0.99687 0.000114216 0.000651276      10      90    100
## 72           0.938 0.99785 0.000495264 0.002351827      60    1400   1460
## 73           0.920 0.99598 0.000206331 0.000088300      28     546    574
## 74           0.973 0.99905 0.000527479 0.001223705      91    2162   2253
## 75           0.993 0.99979 0.003039869 0.009163949     855   40602  41457
## 76           0.997 0.99997 0.003758389 0.009932886    5154  395622 400776
## 77           0.924 0.99701 0.000560733 0.001191281      36     203    239
## 78           0.966 0.99747 0.000128893 0.000786314      26     588    614
## 79           0.965 0.99972 0.000880461 0.001581144     212    7973   8185
## 80           0.953 0.99922 0.000666877 0.001333088      59    2948   3007
## 81           0.996 0.99989 0.002936271 0.019403222    3993  193553 197546
## 82           0.995 0.99994 0.003691336 0.006256828    1533   93748  95281
## 83           0.996 0.99994 0.003657769 0.007137294    2692  140148 142840
## 84           0.968 0.99992 0.000834754 0.001620600     170    4399   4569
## 85           0.996 0.99971 0.002113049 0.009461544    2936  159192 162128
## 86           0.975 0.99994 0.002349450 0.003218537     241    9047   9288
## 87           0.971 0.99858 0.003755648 0.007385268     148    5510   5658
## 88           0.879 0.99666 0.000123273 0.001015320      24     231    255
## 89           0.936 0.99598 0.000212766 0.002765957     118    4578   4696
## 90           0.989 0.99975 0.001741634 0.003576826     687   51940  52627
## 91           0.959 0.99863 0.002416809 0.005861190      28     396    424
## 92           0.925 0.99708 0.000347283 0.000972391      18      84    102
## 93           0.991 0.99940 0.003145478 0.005609436     443   18224  18667
## 94           0.969 0.99988 0.002081381 0.001163995     460   17400  17860
## 95           0.868 0.99487 0.000044600 0.000562907      41     437    478
## 96           0.765 0.99422 0.000028800 0.000289187      10     413    423
## 97           0.982 0.99982 0.001170724 0.004497433     223   13175  13398
## 98           0.991 0.99939 0.003964202 0.007670188     448   19932  20380
## 99           0.996 0.99990 0.002722343 0.009583514    6330  476420 482750
## 100          0.885 0.99585 0.000271465 0.000295475       9     162    171
## 101          0.880 0.99678 0.000019600 0.000535259      19     252    271
## 102          0.988 0.99875 0.000651758 0.001661178     222    6732   6954
## 103          0.970 0.99946 0.001006667 0.002953333     316    8100   8416
## 104          0.783 0.99422 0.000088000 0.000696691      28     434    462
## 105          0.994 0.99995 0.003861728 0.005953086    1235   91776  93011
## 106          0.944 0.99759 0.000413793 0.002620690     294   18876  19170
## 107          0.875 0.99394 0.000102825 0.000621879      17     451    468
## 108          0.985 0.99960 0.001040735 0.003677316     218    4704   4922
## 109          0.965 0.99975 0.001859629 0.000841810     474   16340  16814
## 110          0.959 0.99891 0.000540541 0.002252252     290    5830   6120
## 111          0.996 0.99998 0.005636364 0.014060606    6128  458700 464828
## 112          0.958 0.99809 0.002584261 0.003388100      35    1539   1574
## 113          0.990 0.99951 0.002051581 0.005717138     299   13725  14024
## 114          0.963 0.99921 0.000518296 0.000788513      89    1947   2036
## 115          0.862 0.99376 0.000024500 0.000294836      14     315    329
## 116          0.939 0.99342 0.000292135 0.003001954     165    3888   4053
## 117          0.970 0.99866 0.001000000 0.006300000     567   30200  30767
## 118          0.941 0.99756 0.000194783 0.000427807      16      64     80
## 119          0.995 0.99994 0.003694914 0.014602357    3560  187191 190751
## 120          0.994 0.99991 0.001978261 0.008342512    2403  159960 162363
## 121          0.964 0.99926 0.000369667 0.001059653      75    2183   2258
## 122          0.747 0.99686 0.000021500 0.000205139       9      85     94
## 123          0.809 0.99385 0.000241314 0.001453192      27     392    419
## 124          0.958 0.99915 0.002000000 0.011000000    1082   35211  36293
## 125          0.996 0.99996 0.003753052 0.016133219    5910  380380 386290
## 126          0.989 0.99986 0.001684996 0.003737628     312   18886  19198
## 127          0.903 0.99737 0.000785061 0.000439274      15     105    120
## 128          0.989 0.99949 0.001500000 0.006050000     690   43890  44580
## 129          0.977 0.99957 0.001347628 0.002481144     351   17424  17775
## 130          0.927 0.99487 0.000044300 0.000458078      34     390    424
## 131          0.978 0.99900 0.001056350 0.001705618      92    2006   2098
## 132          0.975 0.99813 0.001080104 0.000620102     125    4453   4578
## 133          0.968 0.99568 0.001047598 0.005574863      37     882    919
## 134          0.993 0.99973 0.001993865 0.005233928     495   21266  21761
## 135          0.996 0.99976 0.003416013 0.004629833    1800   75458  77258
## 136          0.989 0.99927 0.002618758 0.005943971    2186  163680 165866
## 137          0.995 0.99877 0.001561811 0.001915942     973   41715  42688
## 138          0.981 0.99846 0.002909731 0.006790764      58    1504   1562
## 139          0.984 0.99860 0.001925274 0.004212242     250    9504   9754
## 140          0.987 0.99875 0.004288359 0.008478449     277   12483  12760
## 141          0.840 0.99438 0.000045600 0.000385355      19     220    239
## 142          0.981 0.99983 0.000920000 0.003960000     478    9933  10411
## 143          0.986 0.99978 0.004595092 0.002030675     323    5068   5391
## 144          0.980 0.99953 0.000741667 0.003725000     218    6302   6520
## 145          0.972 0.99975 0.000270270 0.001675676     113    2093   2206
## 146          0.997 0.99995 0.035129032 0.070838710    3490  278163 281653
## 147          0.904 0.99748 0.000522581 0.001987097      49    2419   2468
## 148          0.974 0.99938 0.001417208 0.003065729     448   27621  28069
## 149          0.884 0.99496 0.000049200 0.000272283      38     504    542
## 150          0.992 0.99959 0.001987717 0.004287280     212    7956   8168
## 151          0.987 0.99944 0.001406977 0.007372093     557   20502  21059
## 152          0.731 0.99023 0.000029300 0.000437054       8     164    172
## 153          0.997 0.99975 0.001455956 0.004356458     944   30100  31044
## 154          0.992 0.99982 0.003130661 0.006636414     626   26096  26722
## 155          0.996 0.99985 0.002360320 0.007851574    1495   55233  56728
## 156          0.928 0.99806 0.000123967 0.001349174      28     442    470
## 157          0.931 0.99002 0.000721366 0.003820451     437   10920  11357
## 158          0.996 0.99976 0.003082917 0.007494042    2152  118426 120578
## 159          0.987 0.99920 0.000545582 0.001730255      51     360    411
## 160          0.911 0.99581 0.000293924 0.000884557      29     462    491
## 161          0.961 0.99905 0.000419780 0.001512088     209    7326   7535
## 162          0.836 0.98916 0.000150794 0.006021164     146    2256   2402
## 163          0.996 0.99995 0.003215466 0.010685724    3727  255696 259423
## 164          0.995 0.99995 0.003864789 0.010617438    5694  258248 263942
## 165          0.987 0.99960 0.000532873 0.001406018      61    1581   1642
## 166          0.932 0.99702 0.001998042 0.004994729      18     100    118
## 167          0.992 0.99803 0.000353619 0.002718571      98    2079   2177
## 168          0.983 0.99967 0.002547642 0.004338409     224   11060  11284
## 169          0.945 0.99211 0.000070900 0.001611311      45    1053   1098
## 170          0.893 0.99213 0.000035100 0.000302184      18     205    223
## 171          0.976 0.99966 0.000300000 0.003500000     104    1896   2000
## 172          0.962 0.99990 0.000756024 0.002750753     513    3575   4088
## 173          0.977 0.99972 0.001304944 0.002793637     158    4620   4778
## 174          0.974 0.99968 0.001569411 0.002944793     383   18632  19015
## 175          0.949 0.99922 0.002492345 0.004700143     156    4888   5044
## 176          0.962 0.99496 0.001000000 0.005000000     212    8786   8998
## 177          0.866 0.99439 0.000073900 0.000634436      22      78    100
## 178          0.976 0.99886 0.003087140 0.008343407     128    4624   4752
## 179          0.992 0.99976 0.001167608 0.002434087     833   45969  46802
## 180          0.994 0.99988 0.002208504 0.012241060    3064  240120 243184
## 181          0.882 0.99541 0.000020800 0.000336856      17     225    242
## 182          0.992 0.99997 0.002413151 0.008815197    6350  231822 238172
## 183          0.985 0.99969 0.003717802 0.000864605     404   15824  16228
## 184          0.956 0.99855 0.002615322 0.010754309      26     444    470
## 185          0.964 0.99935 0.000135747 0.001628959      67    1056   1123
## 186          0.979 0.99948 0.001765290 0.001029752     247   10528  10775
## 187          0.983 0.99775 0.000521541 0.000717003      37     270    307
## 188          0.900 0.99868 0.000310096 0.000632523      39     448    487
## 189          0.818 0.99432 0.000108071 0.001881840      36     595    631
## 190          0.915 0.99403 0.000157696 0.000707363      21     324    345

The purpose of this assignment is to predict the life expectancy for a county in years, using regression.

Variables Country: name of the country

LifeExp: average life expectancy for the country in years

InfantSurvival: proportion of those surviving to one year or more

Under5Survival: proportion of those surviving to five years or more

TBFree: proportion of the population without TB.

PropMD: proportion of the population who are MDs

PropRN: proportion of the population who are RNs

PersExp: mean personal expenditures on healthcare in US dollars at average exchange rate

GovtExp: mean government expenditures per capita on healthcare, US dollars at average exchange rate TotExp: sum of personal and government expenditures.

Model 1 - LifeExp ~ TotExp

Provide a scatterplot of LifeExp~TotExp, and run simple linear regression. Do not transform the variables. Provide and interpret the F statistics, R^2, standard error,and p-values only. Discuss whether the assumptions of simple linear regression met.

model1 <- lm(LifeExp ~TotExp  , data)
intercept <- coef(model1)[1]
slope <- coef(model1)[2]

ggplot(model1, aes(TotExp, LifeExp))+ 
  geom_point() + 
  geom_abline(slope = slope, intercept = intercept, show.legend = TRUE)

summary(model1)
## 
## Call:
## lm(formula = LifeExp ~ TotExp, data = data)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -24.764  -4.778   3.154   7.116  13.292 
## 
## Coefficients:
##                 Estimate   Std. Error t value Pr(>|t|)    
## (Intercept) 64.753374534  0.753536611  85.933  < 2e-16 ***
## TotExp       0.000062970  0.000007795   8.079 7.71e-14 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 9.371 on 188 degrees of freedom
## Multiple R-squared:  0.2577, Adjusted R-squared:  0.2537 
## F-statistic: 65.26 on 1 and 188 DF,  p-value: 7.714e-14

Model 1 Summary The R2 from this model accounts for 0.2537 of the variability of the data, which means that only 25% of the variance in the response variable can be explained by the independent variable.

Both the y-intercept and TotExp’s p-values are small (near zero), meaning that the probability of observation these relationships due to chance is small.

The Standard error is 9.371.

The linear model is expressed as lifeexp=64.75+0.00006∗x

The F-statistic and p-value indicate that we would reject the null hypothesis (H0), that there isn’t a relationship between the variables.

Model 1 - Evaulation and Residual Analysis

ols_plot_resid_qq(model1)

ols_plot_resid_hist(model1)

ols_plot_resid_fit(model1)

The residual analysis show that the assumptions of linear regression are not met.

Linearity - there does not appear to be a linear relationship

Normality - According to the histogram and Q-Q plot, the residuals are not normally distributed.

Homoscedasticity -

ncvTest(model1)
## Non-constant Variance Score Test 
## Variance formula: ~ fitted.values 
## Chisquare = 2.599177, Df = 1, p = 0.10692

The p-value is greater than .05 - fail to reject H0

Independence -

durbinWatsonTest(model1)
##  lag Autocorrelation D-W Statistic p-value
##    1      0.06872515      1.802451    0.19
##  Alternative hypothesis: rho != 0
gvlma(model1)
## 
## Call:
## lm(formula = LifeExp ~ TotExp, data = data)
## 
## Coefficients:
## (Intercept)       TotExp  
## 64.75337453   0.00006297  
## 
## 
## ASSESSMENT OF THE LINEAR MODEL ASSUMPTIONS
## USING THE GLOBAL TEST ON 4 DEGREES-OF-FREEDOM:
## Level of Significance =  0.05 
## 
## Call:
##  gvlma(x = model1) 
## 
##                        Value          p-value                   Decision
## Global Stat        56.737011 0.00000000001405 Assumptions NOT satisfied!
## Skewness           30.532757 0.00000003282766 Assumptions NOT satisfied!
## Kurtosis            0.002804 0.95777263030755    Assumptions acceptable.
## Link Function      26.074703 0.00000032845930 Assumptions NOT satisfied!
## Heteroscedasticity  0.126747 0.72182921484679    Assumptions acceptable.

Model 2 - Transformations 2.Raise life expectancy to the 4.6 power (i.e., LifeExp^4.6). Raise total expenditures to the 0.06 power (nearly a log transform, TotExp^.06). Plot LifeExp^4.6 as a function of TotExp^.06, and r re-run the simple regression model using the transformed variables. Provide and interpret the F statistics, R^2, standard error, and p-values. Which model is “better?”

LifeExpP <- data$LifeExp^4.6
TotExpP <- data$TotExp^.06

model2 <- lm(LifeExpP~ TotExpP, data)

summary(model2)
## 
## Call:
## lm(formula = LifeExpP ~ TotExpP, data = data)
## 
## Residuals:
##        Min         1Q     Median         3Q        Max 
## -308616089  -53978977   13697187   59139231  211951764 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)    
## (Intercept) -736527910   46817945  -15.73   <2e-16 ***
## TotExpP      620060216   27518940   22.53   <2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 90490000 on 188 degrees of freedom
## Multiple R-squared:  0.7298, Adjusted R-squared:  0.7283 
## F-statistic: 507.7 on 1 and 188 DF,  p-value: < 2.2e-16

Summary The R2 from this model accounts for 0.72283 of the variability of the data, which means that 72% of the variance in the response variable can be explained by the independent variable.

Both the y-intercept and TotExp’s p-values are small (near zero), meaning that the probability of observation these relationships due to chance is small.

The Standard error is 53.6 years

This mode is a vast improvement on the base model from section 1. This model outperforms the previous one.

90490000^(1/4.6)
## [1] 53.66557

The linear model is expressed as lifeexp=64.75+0.00006∗x

The F-statistic and p-value indicate that we would reject the null hypothesis (H0), that there isn’t a relationship between the variables.

intercept <- coef(model2)[1]
slope <- coef(model2)[2]

ggplot(model2, aes(TotExpP, LifeExpP))+ 
  geom_point() + 
  geom_abline(slope = slope, intercept = intercept, show.legend = TRUE)

Residual Analysis

ols_plot_resid_qq(model2)

ols_plot_resid_hist(model2)

ols_plot_resid_fit(model2)

crPlots(model2)

The CRPlot shows that there is now a linear relationship between the variables. While the data is more normalized than previously, there is still a left skew as shown by the histogram and Q-Q plot.

Predictions 3.Using the results from 3, forecast life expectancy when TotExp^.06 =1.5. Then forecast life expectancy when TotExp^.06=2.5.

predictdata <- data.frame(TotExpP=c(1.5,2.5))

predict(model2, predictdata,interval="predict")^(1/4.6)
##        fit      lwr      upr
## 1 63.31153 35.93545 73.00793
## 2 86.50645 81.80643 90.43414

Model 3 Build the following multiple regression model and interpret the F Statistics, R^2, standard error, and p-values. How good is the model? LifeExp = b0+b1 x PropMd + b2 x TotExp +b3 x PropMD x TotExp

model3 <- lm(LifeExp ~ PropMD + TotExp + PropMD * TotExp, data)

Evaulation

summary(model3)
## 
## Call:
## lm(formula = LifeExp ~ PropMD + TotExp + PropMD * TotExp, data = data)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -27.320  -4.132   2.098   6.540  13.074 
## 
## Coefficients:
##                     Estimate     Std. Error t value Pr(>|t|)    
## (Intercept)     62.772703255    0.795605238  78.899  < 2e-16 ***
## PropMD        1497.493952519  278.816879652   5.371 2.32e-07 ***
## TotExp           0.000072333    0.000008982   8.053 9.39e-14 ***
## PropMD:TotExp   -0.006025686    0.001472357  -4.093 6.35e-05 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 8.765 on 186 degrees of freedom
## Multiple R-squared:  0.3574, Adjusted R-squared:  0.3471 
## F-statistic: 34.49 on 3 and 186 DF,  p-value: < 2.2e-16

The adj R2 accounts for 0.3471 of the variability of the data, which means that only 34% of the variance in the response variable can be explained by the independent variable.

Both the y-intercept and other variables p-value or low (near zero), meaning that the probability of observation these relationships due to chance is small.

The F-statistic and p-value indicate that we would reject the null hypothesis (H0), that there isn’t a relationship between the variables.

Residual Analysis

ols_plot_resid_qq(model3)

ols_plot_resid_hist(model3)

ols_plot_resid_fit(model3)

The data does not resemble a normal distribution, as shown in the histogram (left skew) and the Q-Q pllots. The residuals do not appear to be centered around 0 from the residual plot.

Predictions Forecast LifeExp when PropMD=.03 and TotExp = 14. Does this forecast seem realistic? Why or why not?

predictdata2 <- data.frame(PropMD=0.03, TotExp=14)

predict(model3, predictdata2,interval="predict")
##       fit      lwr      upr
## 1 107.696 84.24791 131.1441

The predicted range of vaulues appear to be too high. The max value shows to be around 83. The data is predicting a much higher fit and CI.