Software Statistic

Introducere

author: Rodica Ioana Lung date: 26.02.2020

========================================================

Scurta istorie a R

Open source??

Ce este R?

R is an limbaj de programare interpretat - majoritatea functiilor sunt scrise in R - se pot combina cu proceduri in C, C+, or FORTRAN - se pot apela comenzi de sistem din R

R este folosit pentru manipulare de date, statistica si grafice. Foloseste: - operatori (+ - <- * %*% .) pentru calcule - o colectie uriasa de functii - facilitati de reprezentare grafica - pachete de functii scrise de utilizatori: 800+

De ce?

Avantaje

Mai mult de 800 pachete

cran.r-project.org/src/contrib/PACKAGES.html

Cum se invata R?

install.packages('swirl')
library('swirl')
swirl()

R Studio

setwd("E:/Dropbox/FSEGA/cursuri/2016-2017/semestrul 2/R/curs1")

Exemplu de cod

incremental:true

data(cars)
summary(cars)
     speed           dist       
 Min.   : 4.0   Min.   :  2.00  
 1st Qu.:12.0   1st Qu.: 26.00  
 Median :15.0   Median : 36.00  
 Mean   :15.4   Mean   : 42.98  
 3rd Qu.:19.0   3rd Qu.: 56.00  
 Max.   :25.0   Max.   :120.00  

Cu grafic

incremental:true

plot(cars)
plot of chunk unnamed-chunk-4

plot of chunk unnamed-chunk-4

Exemple

incremental:true

data(mtcars)
summary(mtcars)
      mpg             cyl             disp             hp       
 Min.   :10.40   Min.   :4.000   Min.   : 71.1   Min.   : 52.0  
 1st Qu.:15.43   1st Qu.:4.000   1st Qu.:120.8   1st Qu.: 96.5  
 Median :19.20   Median :6.000   Median :196.3   Median :123.0  
 Mean   :20.09   Mean   :6.188   Mean   :230.7   Mean   :146.7  
 3rd Qu.:22.80   3rd Qu.:8.000   3rd Qu.:326.0   3rd Qu.:180.0  
 Max.   :33.90   Max.   :8.000   Max.   :472.0   Max.   :335.0  
      drat             wt             qsec             vs        
 Min.   :2.760   Min.   :1.513   Min.   :14.50   Min.   :0.0000  
 1st Qu.:3.080   1st Qu.:2.581   1st Qu.:16.89   1st Qu.:0.0000  
 Median :3.695   Median :3.325   Median :17.71   Median :0.0000  
 Mean   :3.597   Mean   :3.217   Mean   :17.85   Mean   :0.4375  
 3rd Qu.:3.920   3rd Qu.:3.610   3rd Qu.:18.90   3rd Qu.:1.0000  
 Max.   :4.930   Max.   :5.424   Max.   :22.90   Max.   :1.0000  
       am              gear            carb      
 Min.   :0.0000   Min.   :3.000   Min.   :1.000  
 1st Qu.:0.0000   1st Qu.:3.000   1st Qu.:2.000  
 Median :0.0000   Median :4.000   Median :2.000  
 Mean   :0.4062   Mean   :3.688   Mean   :2.812  
 3rd Qu.:1.0000   3rd Qu.:4.000   3rd Qu.:4.000  
 Max.   :1.0000   Max.   :5.000   Max.   :8.000  

Exemple cont.

incremental:true

mtcars$wt
 [1] 2.620 2.875 2.320 3.215 3.440 3.460 3.570 3.190 3.150 3.440 3.440
[12] 4.070 3.730 3.780 5.250 5.424 5.345 2.200 1.615 1.835 2.465 3.520
[23] 3.435 3.840 3.845 1.935 2.140 1.513 3.170 2.770 3.570 2.780
mean(mtcars$wt)
[1] 3.21725

?mean afiseaza Help pt functia mean

Tipuri de baza

incremental:true

Vector

a=c(1,2,3)
a
[1] 1 2 3
a=c(a,100:120)
a
 [1]   1   2   3 100 101 102 103 104 105 106 107 108 109 110 111 112 113
[18] 114 115 116 117 118 119 120

=== incremental:true

a[4]
[1] 100
a[2:6]
[1]   2   3 100 101 102
a[5]=3456
a[5]
[1] 3456
a[1:10]
 [1]    1    2    3  100 3456  102  103  104  105  106
a[c(4,5,9)]
[1]  100 3456  105

=== incremental:true

Atribuirile se fac cu <- sau ALT-

nume <- c("Ana", "Maria",
              "Angela","Andrei",
              "Mihai", "Ioana",
              "Lucian") 



nume
[1] "Ana"    "Maria"  "Angela" "Andrei" "Mihai"  "Ioana"  "Lucian"
numbers <- c(1:10)

numbers
 [1]  1  2  3  4  5  6  7  8  9 10
numbers <- c(numbers, 11:20)

numbers
 [1]  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20

==== incremental:true

nume <- c("Ana", "Maria",
          "Angela","Andrei",
          "Mihai", "Ioana",
          "Lucian", 'NUMELEVOSTRU')


mystery = nchar(nume)
mystery
[1]  3  5  6  6  5  5  6 12
mystery == 6
[1] FALSE FALSE  TRUE  TRUE FALSE FALSE  TRUE FALSE
nume[mystery == 6]
[1] "Angela" "Andrei" "Lucian"

=== incremental:true

data(mtcars)
names(mtcars)
 [1] "mpg"  "cyl"  "disp" "hp"   "drat" "wt"   "qsec" "vs"   "am"   "gear"
[11] "carb"
?mtcars

=== incremental:true

mtcars
                     mpg cyl  disp  hp drat    wt  qsec vs am gear carb
Mazda RX4           21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
Mazda RX4 Wag       21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
Datsun 710          22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
Hornet 4 Drive      21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
Hornet Sportabout   18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
Valiant             18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
Merc 240D           24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
Merc 230            22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
Merc 280            19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
Merc 280C           17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
Merc 450SE          16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
Merc 450SL          17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
Merc 450SLC         15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
Cadillac Fleetwood  10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
Fiat 128            32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
Honda Civic         30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
Toyota Corolla      33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
Toyota Corona       21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
Dodge Challenger    15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
AMC Javelin         15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
Camaro Z28          13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
Pontiac Firebird    19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
Fiat X1-9           27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
Porsche 914-2       26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
Lotus Europa        30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
Ford Pantera L      15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
Ferrari Dino        19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
Maserati Bora       15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
Volvo 142E          21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2

==== incremental:true

str(mtcars)
'data.frame':   32 obs. of  11 variables:
 $ mpg : num  21 21 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 ...
 $ cyl : num  6 6 4 6 8 6 8 4 4 6 ...
 $ disp: num  160 160 108 258 360 ...
 $ hp  : num  110 110 93 110 175 105 245 62 95 123 ...
 $ drat: num  3.9 3.9 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 ...
 $ wt  : num  2.62 2.88 2.32 3.21 3.44 ...
 $ qsec: num  16.5 17 18.6 19.4 17 ...
 $ vs  : num  0 0 1 1 0 1 0 1 1 1 ...
 $ am  : num  1 1 1 0 0 0 0 0 0 0 ...
 $ gear: num  4 4 4 3 3 3 3 4 4 4 ...
 $ carb: num  4 4 1 1 2 1 4 2 2 4 ...
dim(mtcars)
[1] 32 11

=== incremental:true

rownames(mtcars)
 [1] "Mazda RX4"           "Mazda RX4 Wag"       "Datsun 710"         
 [4] "Hornet 4 Drive"      "Hornet Sportabout"   "Valiant"            
 [7] "Duster 360"          "Merc 240D"           "Merc 230"           
[10] "Merc 280"            "Merc 280C"           "Merc 450SE"         
[13] "Merc 450SL"          "Merc 450SLC"         "Cadillac Fleetwood" 
[16] "Lincoln Continental" "Chrysler Imperial"   "Fiat 128"           
[19] "Honda Civic"         "Toyota Corolla"      "Toyota Corona"      
[22] "Dodge Challenger"    "AMC Javelin"         "Camaro Z28"         
[25] "Pontiac Firebird"    "Fiat X1-9"           "Porsche 914-2"      
[28] "Lotus Europa"        "Ford Pantera L"      "Ferrari Dino"       
[31] "Maserati Bora"       "Volvo 142E"         
colnames(mtcars)
 [1] "mpg"  "cyl"  "disp" "hp"   "drat" "wt"   "qsec" "vs"   "am"   "gear"
[11] "carb"

=== incremental:true

rownames(mtcars) <- c(1:32)
mtcars
    mpg cyl  disp  hp drat    wt  qsec vs am gear carb
1  21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
2  21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
3  22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
4  21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
5  18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
6  18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
7  14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
8  24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
9  22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
10 19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
11 17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
12 16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
13 17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
14 15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
15 10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
16 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
17 14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
18 32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
19 30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
20 33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
21 21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
22 15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
23 15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
24 13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
25 19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
26 27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
27 26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
28 30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
29 15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
30 19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
31 15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
32 21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2

=== incremental:true

data(mtcars)
head(mtcars, 10)
                   mpg cyl  disp  hp drat    wt  qsec vs am gear carb
Mazda RX4         21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
Mazda RX4 Wag     21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
Datsun 710        22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
Hornet 4 Drive    21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
Hornet Sportabout 18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
Valiant           18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
Duster 360        14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
Merc 240D         24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
Merc 230          22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
Merc 280          19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4

===

head(mtcars)
                   mpg cyl disp  hp drat    wt  qsec vs am gear carb
Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
Datsun 710        22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1

=== incremental:true

tail(mtcars, 3)
               mpg cyl disp  hp drat   wt qsec vs am gear carb
Ferrari Dino  19.7   6  145 175 3.62 2.77 15.5  0  1    5    6
Maserati Bora 15.0   8  301 335 3.54 3.57 14.6  0  1    5    8
Volvo 142E    21.4   4  121 109 4.11 2.78 18.6  1  1    4    2
tail(mtcars)
                mpg cyl  disp  hp drat    wt qsec vs am gear carb
Porsche 914-2  26.0   4 120.3  91 4.43 2.140 16.7  0  1    5    2
Lotus Europa   30.4   4  95.1 113 3.77 1.513 16.9  1  1    5    2
Ford Pantera L 15.8   8 351.0 264 4.22 3.170 14.5  0  1    5    4
Ferrari Dino   19.7   6 145.0 175 3.62 2.770 15.5  0  1    5    6
Maserati Bora  15.0   8 301.0 335 3.54 3.570 14.6  0  1    5    8
Volvo 142E     21.4   4 121.0 109 4.11 2.780 18.6  1  1    4    2

===

mtcars$mpg
 [1] 21.0 21.0 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 17.8 16.4 17.3 15.2
[15] 10.4 10.4 14.7 32.4 30.4 33.9 21.5 15.5 15.2 13.3 19.2 27.3 26.0 30.4
[29] 15.8 19.7 15.0 21.4
mean(mtcars$mpg)
[1] 20.09062

am aflat despre:

  c, nchar, data, str, dim, names, row.names, head, tail, mean

=== incremental:true

state<-read.csv("E:/Dropbox/FSEGA/cursuri/2016-2017/semestrul 2/R/date/stateData.csv")

Fie trecem doar numele fisierului (in ghilimele) daca e in directorul de lucru, fie trecem calea intreaga catre fisier.

str(state)
'data.frame':   50 obs. of  12 variables:
 $ X             : Factor w/ 50 levels "Alabama","Alaska",..: 1 2 3 4 5 6 7 8 9 10 ...
 $ state.abb     : Factor w/ 50 levels "AK","AL","AR",..: 2 1 4 3 5 6 7 8 9 10 ...
 $ state.area    : int  51609 589757 113909 53104 158693 104247 5009 2057 58560 58876 ...
 $ state.region  : int  2 4 4 2 4 4 1 2 2 2 ...
 $ population    : int  3615 365 2212 2110 21198 2541 3100 579 8277 4931 ...
 $ income        : int  3624 6315 4530 3378 5114 4884 5348 4809 4815 4091 ...
 $ illiteracy    : num  2.1 1.5 1.8 1.9 1.1 0.7 1.1 0.9 1.3 2 ...
 $ life.exp      : num  69 69.3 70.5 70.7 71.7 ...
 $ murder        : num  15.1 11.3 7.8 10.1 10.3 6.8 3.1 6.2 10.7 13.9 ...
 $ highSchoolGrad: num  41.3 66.7 58.1 39.9 62.6 63.9 56 54.6 52.6 40.6 ...
 $ frost         : int  20 152 15 65 20 166 139 103 11 60 ...
 $ area          : int  50708 566432 113417 51945 156361 103766 4862 1982 54090 58073 ...

=== incremental:true

head(state)
           X state.abb state.area state.region population income
1    Alabama        AL      51609            2       3615   3624
2     Alaska        AK     589757            4        365   6315
3    Arizona        AZ     113909            4       2212   4530
4   Arkansas        AR      53104            2       2110   3378
5 California        CA     158693            4      21198   5114
6   Colorado        CO     104247            4       2541   4884
  illiteracy life.exp murder highSchoolGrad frost   area
1        2.1    69.05   15.1           41.3    20  50708
2        1.5    69.31   11.3           66.7   152 566432
3        1.8    70.55    7.8           58.1    15 113417
4        1.9    70.66   10.1           39.9    65  51945
5        1.1    71.71   10.3           62.6    20 156361
6        0.7    72.06    6.8           63.9   166 103766

Filtrare date

incremental:true

subset(state,state.region==1)
               X state.abb state.area state.region population income
7    Connecticut        CT       5009            1       3100   5348
19         Maine        ME      33215            1       1058   3694
21 Massachusetts        MA       8257            1       5814   4755
29 New Hampshire        NH       9304            1        812   4281
30    New Jersey        NJ       7836            1       7333   5237
32      New York        NY      49576            1      18076   4903
38  Pennsylvania        PA      45333            1      11860   4449
39  Rhode Island        RI       1214            1        931   4558
45       Vermont        VT       9609            1        472   3907
   illiteracy life.exp murder highSchoolGrad frost  area
7         1.1    72.48    3.1           56.0   139  4862
19        0.7    70.39    2.7           54.7   161 30920
21        1.1    71.83    3.3           58.5   103  7826
29        0.7    71.23    3.3           57.6   174  9027
30        1.1    70.93    5.2           52.5   115  7521
32        1.4    70.55   10.9           52.7    82 47831
38        1.0    70.43    6.1           50.2   126 44966
39        1.3    71.90    2.4           46.4   127  1049
45        0.6    71.64    5.5           57.1   168  9267

=== incremental:true

nordestsubset <- subset(state,state.region==1)
head(nordestsubset)
               X state.abb state.area state.region population income
7    Connecticut        CT       5009            1       3100   5348
19         Maine        ME      33215            1       1058   3694
21 Massachusetts        MA       8257            1       5814   4755
29 New Hampshire        NH       9304            1        812   4281
30    New Jersey        NJ       7836            1       7333   5237
32      New York        NY      49576            1      18076   4903
   illiteracy life.exp murder highSchoolGrad frost  area
7         1.1    72.48    3.1           56.0   139  4862
19        0.7    70.39    2.7           54.7   161 30920
21        1.1    71.83    3.3           58.5   103  7826
29        0.7    71.23    3.3           57.6   174  9027
30        1.1    70.93    5.2           52.5   115  7521
32        1.4    70.55   10.9           52.7    82 47831
dim(nordestsubset)
[1]  9 12

dataset[rows,columns]

incremental:true

state[state$state.region==3,]
              X state.abb state.area state.region population income
13     Illinois        IL      56400            3      11197   5107
14      Indiana        IN      36291            3       5313   4458
15         Iowa        IA      56290            3       2861   4628
16       Kansas        KS      82264            3       2280   4669
22     Michigan        MI      58216            3       9111   4751
23    Minnesota        MN      84068            3       3921   4675
25     Missouri        MO      69686            3       4767   4254
27     Nebraska        NE      77227            3       1544   4508
34 North Dakota        ND      70665            3        637   5087
35         Ohio        OH      41222            3      10735   4561
41 South Dakota        SD      77047            3        681   4167
49    Wisconsin        WI      56154            3       4589   4468
   illiteracy life.exp murder highSchoolGrad frost  area
13        0.9    70.14   10.3           52.6   127 55748
14        0.7    70.88    7.1           52.9   122 36097
15        0.5    72.56    2.3           59.0   140 55941
16        0.6    72.58    4.5           59.9   114 81787
22        0.9    70.63   11.1           52.8   125 56817
23        0.6    72.96    2.3           57.6   160 79289
25        0.8    70.69    9.3           48.8   108 68995
27        0.6    72.60    2.9           59.3   139 76483
34        0.8    72.78    1.4           50.3   186 69273
35        0.8    70.82    7.4           53.2   124 40975
41        0.5    72.08    1.7           53.3   172 75955
49        0.7    72.48    3.0           54.5   149 54464

=== incremental:true

state[state$state.region==3,c(1,2)]
              X state.abb
13     Illinois        IL
14      Indiana        IN
15         Iowa        IA
16       Kansas        KS
22     Michigan        MI
23    Minnesota        MN
25     Missouri        MO
27     Nebraska        NE
34 North Dakota        ND
35         Ohio        OH
41 South Dakota        SD
49    Wisconsin        WI

=== incremental:true

nordest=state[state$state.region==1,]
head(nordest)
               X state.abb state.area state.region population income
7    Connecticut        CT       5009            1       3100   5348
19         Maine        ME      33215            1       1058   3694
21 Massachusetts        MA       8257            1       5814   4755
29 New Hampshire        NH       9304            1        812   4281
30    New Jersey        NJ       7836            1       7333   5237
32      New York        NY      49576            1      18076   4903
   illiteracy life.exp murder highSchoolGrad frost  area
7         1.1    72.48    3.1           56.0   139  4862
19        0.7    70.39    2.7           54.7   161 30920
21        1.1    71.83    3.3           58.5   103  7826
29        0.7    71.23    3.3           57.6   174  9027
30        1.1    70.93    5.2           52.5   115  7521
32        1.4    70.55   10.9           52.7    82 47831
dim(nordest)
[1]  9 12

Exercitii:

cu tabelul stateData.csv:

  1. Selectati observatiile corespunzand statelor din regiunea 3; definiti o variabila in care sa le pastrati;
  2. Selectati observatiile corespunzand statelor cu populatie mai mica de 2000;
  3. La punctele 1 si 2 selectati doar numele statelor
  4. La fel, dar alegeti numele statelor, populatia si aria.

Tema:

Tot cu tabelul stateData.csv

  1. Importati tabelul in R
  2. Afisati dimensiunea tabelului
  3. Afisati structura tabelului
  4. Afisati primele 6 observatii
  5. Afisati ultimele 4 observatii
  6. Calculati media var population
  7. Calculati mediana var population
  8. Calculati max var life.exp
  9. Calculati min var state.area
  10. Selectati statele cu populatie peste 2000 si illiteracy sub 1
  11. Cate sunt?
  12. Selectati statele cu populatie sub 2000 si income sub 4000
  13. Selectati statele cu murder peste 10 si income sub 4000