Exercise on Combined and Separate Ratio Estimation

Tasks :

(Item 1)

Delete all observations with missing values for the variable ACRES92 and ACRES87.

(Item 2)

Construct separate datasets according to the 4 REGIONS.

(Item 3)

Using set.seed(last 5 digits of your std no), draw a random sample of size 300
and estimate the population mean and total of ACRES92(under SRS).

(Item 4)

Using
set.seed (last 5 digits of your std no + 10) obtain a sample of size 21 from the Northeast stratum.
set.seed (last 5 digits of your std no + 11) obtain a sample of size 103 from the NorthCentral stratum.
set.seed (last 5 digits of your std no + 12) obtain a sample of size 135 from the South stratum.
set.seed (last 5 digits of your std no + 13) obtain a sample of size 41 from the West stratum.

(Item 5)

Estimate the population mean and total of ACRES92 using a ratio estimator with ACRES87 as auxiliary variable. (p. 119, eqn. (42))

(Item 6)

Estimate the population total using a combined ratio estimator.
(see p.144 and equation 3.2 from p.78).

(Item 7)

Estimate the population total using a separate ratio estimator. (see p.144).
##############################################
############  STAT 250 Exercise  #############
############   08-Nov-2018       #############
############ John Pauline Pineda #############
##############################################

# Set working directory
setwd("F:/SamplingDesign")

Item 1

##############################################
############       ITEM 1        #############
##############################################
# Delete all observations with missing values 
# for the variable ACRES92 and ACRES87.
##############################################

# Load the working data
agpop <- read.csv("agpop.dat")

# Initial exploratory analysis

# Check the data dimensions
# 3078 rows and 15 columns
dim(agpop) 
## [1] 3078   15
# Generate the data summary
summary(agpop)
##                COUNTY         STATE         ACRES92       
##  WASHINGTON COUNTY:  30   TX     : 254   Min.   :    -99  
##  JEFFERSON COUNTY :  25   GA     : 159   1st Qu.:  80903  
##  FRANKLIN COUNTY  :  24   KY     : 120   Median : 191648  
##  JACKSON COUNTY   :  23   MO     : 114   Mean   : 306677  
##  LINCOLN COUNTY   :  23   KS     : 105   3rd Qu.: 366886  
##  MADISON COUNTY   :  19   IL     : 102   Max.   :7229585  
##  (Other)          :2934   (Other):2224                    
##     ACRES87           ACRES82           FARMS92          FARMS87      
##  Min.   :    -99   Min.   :    -99   Min.   :   0.0   Min.   :   0.0  
##  1st Qu.:  86236   1st Qu.:  96397   1st Qu.: 295.0   1st Qu.: 318.5  
##  Median : 199864   Median : 207292   Median : 521.0   Median : 572.0  
##  Mean   : 313016   Mean   : 320194   Mean   : 625.5   Mean   : 678.3  
##  3rd Qu.: 372224   3rd Qu.: 377065   3rd Qu.: 838.0   3rd Qu.: 921.0  
##  Max.   :7687460   Max.   :7313958   Max.   :7021.0   Max.   :7590.0  
##                                                                       
##     FARMS82          LARGEF92         LARGEF87         LARGEF82     
##  Min.   :   0.0   Min.   :  0.00   Min.   :  0.00   Min.   :  0.00  
##  1st Qu.: 345.0   1st Qu.:  8.00   1st Qu.:  8.00   1st Qu.:  8.00  
##  Median : 616.0   Median : 30.00   Median : 27.00   Median : 25.00  
##  Mean   : 728.1   Mean   : 56.18   Mean   : 54.86   Mean   : 52.62  
##  3rd Qu.: 991.0   3rd Qu.: 75.00   3rd Qu.: 70.00   3rd Qu.: 65.00  
##  Max.   :7394.0   Max.   :579.00   Max.   :596.00   Max.   :546.00  
##                                                                     
##     SMALLF92          SMALLF87          SMALLF82       REGION   
##  Min.   :   0.00   Min.   :   0.00   Min.   :   0.00   NC:1054  
##  1st Qu.:  13.00   1st Qu.:  17.00   1st Qu.:  16.00   NE: 220  
##  Median :  29.00   Median :  35.00   Median :  34.00   S :1382  
##  Mean   :  54.09   Mean   :  59.54   Mean   :  60.97   W : 422  
##  3rd Qu.:  59.00   3rd Qu.:  67.00   3rd Qu.:  67.00            
##  Max.   :4298.00   Max.   :3654.00   Max.   :3522.00            
## 
# Count the number of rows with missing values for the ACRES92 column
# 19 rows with missing values
nrow(agpop[agpop$ACRES92==-99,])
## [1] 19
# Count the number of rows with missing values for the ACRES87 column
# 23 rows with missing values
nrow(agpop[agpop$ACRES87==-99,])
## [1] 23
# Remove missing values and only keep the needed columns
agpop_complete <- agpop[agpop$ACRES92!=-99,c("ACRES92","ACRES87","REGION")]

# Remove missing values and only keep the needed columns
agpop_complete <- agpop_complete[agpop_complete$ACRES87!=-99,c("ACRES92","ACRES87","REGION")]

# Check the data dimensions
# 3044 rows and 3 columns
dim(agpop_complete)
## [1] 3044    3
(N <- nrow(agpop_complete))
## [1] 3044
# Double check if all missing rows have been indeed removed
# Count the number of rows with missing values for the ACRES92 column
# 0 rows with missing values
nrow(agpop_complete[agpop_complete$ACRES92==-99,])
## [1] 0
# Count the number of rows with missing values for the ACRES87 column
# 0 rows with missing values
nrow(agpop_complete[agpop_complete$ACRES87==-99,])
## [1] 0
# Generate the population means
# Population mean for ACRES92 is 309900.4
(ACRES92_popmean <- mean(agpop_complete$ACRES92))
## [1] 309900.4
# Population mean for ACRES87 is 316094.7
(ACRES87_popmean <- mean(agpop_complete$ACRES87))
## [1] 316094.7
# Generate the population totals
# Population total for ACRES92 is 943336889
(ACRES92_poptotal <- sum(agpop_complete$ACRES92))
## [1] 943336889
# Population total for ACRES87 is 962192213
(ACRES87_poptotal <- sum(agpop_complete$ACRES87))
## [1] 962192213

Item 2

##############################################
############       ITEM 2        #############
##############################################
# Construct separate datasets 
# according to the 4 REGIONS.  
##############################################

# Specify the number of strata
(H <- nlevels(agpop_complete$REGION))
## [1] 4
# Create data objects for the regions / strata
NEregion <- agpop_complete[agpop_complete$REGION=="NE",]
NCregion <- agpop_complete[agpop_complete$REGION=="NC",]
Sregion <- agpop_complete[agpop_complete$REGION=="S",]
Wregion <- agpop_complete[agpop_complete$REGION=="W",]

# Specify the population size per stratum
# North East region stratum population size = 211
(N.NEregion <- nrow(NEregion))
## [1] 211
# North Central region stratum population size = 1049
(N.NCregion <- nrow(NCregion))
## [1] 1049
# South region stratum population size = 1370
(N.Sregion <- nrow(Sregion))
## [1] 1370
# West region stratum population size = 414
(N.Wregion <- nrow(Wregion))
## [1] 414

Item 3

##############################################
############       ITEM 3        #############
##############################################
# Using set.seed(last 5 digits of your std no)
# draw a random sample of size 300 and 
# estimate the population mean 
# and total of ACRES92 (under SRS).
##############################################

# Set the seed numbers
(seedSRS0 <- 89176)
## [1] 89176
# Specify the sample size
(n <- 300)
## [1] 300
# Verify the population size
# Population size is 3044
(N)
## [1] 3044
# Generate the sample indices
set.seed(seedSRS0)
(sampleindices <- sample(N,n))
##   [1]  599  163 2028 1437  730 1538 2375  233 1917  522 2170 1226 2105  700
##  [15] 2853 2180 2628 2332  809  962  613 2079   79 1157 2484 1348 1483  330
##  [29] 2343 2864 2709 1578  618 2656 2269  778 3004   71 1644 2717  465 1372
##  [43]  161 2661 1534 2862  918 1687 1569  516  542 1758   96   98  877 2521
##  [57] 1901  719 1688  331  129 2149 2597  548  246 2487  298 1562  269 2538
##  [71] 1015 1890  347 2617 2643  395 1683 2926 2930 1560 2962 2024  122 1421
##  [85] 1926  954 1109 2473  636 2820    7  178  534 1443 1657  555 1910  996
##  [99] 2379 1357  267 1051 2659 2705 1107 1245  898 1432 1738 1748 2413 1149
## [113]  819 2784 1013  950   20  334 2427  958 1770 1902 1718 2002 1118  982
## [127]   26  540 1547 2664   57 1832 1907 2179  736 1121  876 1044 2443 2047
## [141] 2857 2400  869 2624  206 1871  105  662   35 2005 2680 1373 1222 2244
## [155]  328 1228  398 2577 2471  573 2238  294 2466 1807  204 2585 1788 2746
## [169] 1299 1064 1512 2640 1069 1597 1301 1615 2785  977  840 2497 1816  785
## [183] 2575  967  776 2032 2772 2492 1076  928 1965  130 1593 2322 2459 1684
## [197]   17 1159 2421 1446 2035 1649   47 1316 2470 2237  313 2092 3014  454
## [211] 2988 2333 1389 1556  731  370 2518  397 1714  879 2947 1376 2595 2478
## [225] 1175 2221 2950 1834 1145 1861 1235  570 1740 1634 2132 2843 1517 1530
## [239] 1784 1575 1489  300 2318 1195 2683 2657 2178 1848  577  752 1859 2293
## [253] 1283  925   72 2605  854  838 2568 1275  771 2946 1135 2261  249   40
## [267] 2342 1847 1264 2069  892  225 2750 2462 1453 1515  595  403  689  887
## [281] 2441  910  697 1473 2540 2279 1148 2825  366 1959   74 1858 2315  993
## [295] 2846 2817 1119 2767 2644  920
# Generate the actual samples
(agpop_sampled <- agpop_complete[sampleindices,])
##      ACRES92 ACRES87 REGION
## 606   233217  230461     NC
## 163   286288  241276      W
## 2050  230988  251969     NC
## 1449  316809  300812     NC
## 737   184599  184566     NC
## 1550  181946  177963      S
## 2399 1406379 1397710     NC
## 234   156801  150334      W
## 1933 1797466 1805222      W
## 529   268506  268437     NC
## 2192 1457339 1519876      W
## 1236  193688  207726     NC
## 2127  419760  404416      S
## 707   258014  262198     NC
## 2882   24848   28234     NE
## 2202 1318447 1381625      W
## 2654  547428  548293      S
## 2356  974811 1009978     NC
## 816   158788  172226     NC
## 969    90033   89986      S
## 620   357684  377025     NC
## 2101  302456  318255     NC
## 79     18818   19659      S
## 1167   83232   92806      S
## 2508  416631  422998      S
## 1360  231610  234126     NC
## 1495  151743  173064      S
## 335   299699  329388      S
## 2367  545064  486467     NC
## 2893  112085  115566      W
## 2735  644730  685935      S
## 1590 1644001 1722206      W
## 625   221209  207722      W
## 2682  402011  546742      S
## 2293   74733   85937      S
## 785   202429  209556     NC
## 3038  115487  118540      S
## 71    141260  156950      S
## 1658  180400  182498      S
## 2743  461127  402967      S
## 472    44470   54722      S
## 1384  181292  189383     NC
## 161  2108834 2358559      W
## 2687  362642  318164      S
## 1546   86096   87159      S
## 2891  274546  274119      W
## 925   409839  396556     NC
## 1701  144858  154350      S
## 1581  135126  152109      W
## 523   214452  224153      W
## 549   312173  328319     NC
## 1772 1269572 1300508     NC
## 96    168755  165498      S
## 98     42794   41293      S
## 884   222028  223426     NC
## 2545  471498  499983      S
## 1916 2149450 2220431      W
## 726   402310  444816     NC
## 1702   51916   54858      S
## 336   296242  311074      S
## 129   122871  112409      S
## 2171  421233  435566      S
## 2622  383573  403124      S
## 555   343870  334112     NC
## 248   641755  643050      W
## 2511  629681  593971      S
## 302   227202  214364      S
## 1574  598694  536553      W
## 272   546538  505471      W
## 2562  518788  589050      S
## 1022   44709   55183      S
## 1905 3112271 2991513      W
## 352   151242  166766      S
## 2643  558553  517379      S
## 2669  525885  505366      S
## 402    25802   27899      S
## 1697   68736   75808      S
## 2955  218145  228959     NC
## 2959  170228  183626     NC
## 1572 2338866 2433747      W
## 2994   86091  100728     NC
## 2046  275644  288175     NC
## 122    69422   80104      S
## 1433  199292  201016     NC
## 1942  738041  833913      W
## 961   471658  529749     NC
## 1116   27469   26993      S
## 2497  103063  103622      S
## 643   353528  401677      W
## 2849   48889   41268      S
## 7     167832  192082      S
## 178   775829  702173      W
## 541   308497  317974     NC
## 1455  323465  336976     NC
## 1671   75496   91744      S
## 562   317205  319657     NC
## 1926  770155  788473      W
## 1003   86074   96982      S
## 2403   93098   88616      S
## 1369  249731  252824     NC
## 270  1004360  882165      W
## 1058  159794  161234      S
## 2685  497106  445493      S
## 2731  242901  276750      S
## 1114   87574   89425      S
## 1256   73437   76193     NC
## 905   271713  263592     NC
## 1444  201714  206871     NC
## 1752 1165695 1122980     NC
## 1762  485012  487285     NC
## 2437  224247  222142      S
## 1157   37477   46747     NE
## 826   184118  197875     NC
## 2812   73097   71550      S
## 1020  144828  144862      S
## 957   687593  704788     NC
## 20     47200   49177      S
## 339    44962   48999      S
## 2451  275219  279482      S
## 965   265978  253967     NC
## 1784  437826  442540     NC
## 1917 1881764 1894215      W
## 1732  559385  609823     NC
## 2024  122480  117130     NC
## 1125  193137  195787      S
## 989   192189  201861      S
## 26    111315  118184      S
## 547   368114  376952     NC
## 1559  230524  245244      S
## 2690  667177  529092      S
## 57    155914  159757      S
## 1846  532901  570445     NC
## 1923 1769177 1635787      W
## 2201  380464  391692      W
## 743    67998   75234     NC
## 1128  247106  244811      S
## 883   201798  216179     NC
## 1051  136869  137344      S
## 2467   53026   58327      S
## 2069  200405  209643     NC
## 2886  132674  140177     NE
## 2424   70457   78611      S
## 876   407464  397383     NC
## 2650  515960  543283      S
## 207   388084  377352      W
## 1885    7799   10033     NE
## 105   183895  173516      S
## 669    69354   73076     NC
## 35    130063  127653      S
## 2027   99214  115999     NC
## 2706  247626  249326      S
## 1385  255498  260645     NC
## 1232  277400  282467     NC
## 2268   90065   95605     NE
## 333    11738   17507      S
## 1238   47308   47988     NC
## 405     3046    3841      S
## 2602  660412  762442      S
## 2495  352488  350886      S
## 580   266083  266090     NC
## 2261   44425   56734     NE
## 298    36230   41178      S
## 2490  125092  135209      S
## 1821  401978  403549     NC
## 205   342653  347504      W
## 2610  345138  348386      S
## 1802  658572  709723     NC
## 2772 1294703 1318672      W
## 1311  379603  389539     NC
## 1071  154082  164293      S
## 1524   53401   57612      S
## 2666   73948   75350      S
## 1076  165015  174061      S
## 1609  683088  704878      W
## 1313   79183   91078     NC
## 1627   52974   57431      S
## 2813   24478   25831      S
## 984   137337  137781      S
## 847    79235   86245     NC
## 2521  548351  509782      S
## 1830  446007  474848     NC
## 792   229097  234599     NC
## 2600  545664  615426      S
## 974    80864   84750      S
## 783   222435  228419     NC
## 2054   74461   79180     NC
## 2799   68326   72611      S
## 2516 2405018 2377767      S
## 1083  140432  136561      S
## 935   582053  542578     NC
## 1985  242637  285731     NE
## 130   156363  156212      S
## 1605 1968857 1938423      W
## 2346  236608  236960     NC
## 2483  183178  190772      S
## 1698  115854  117441      S
## 17     67950   84626      S
## 1169  126981  132804      S
## 2445   54518   62446      S
## 1458  138986  139937     NC
## 2057   17138   18335     NC
## 1663    8882    7533      S
## 47    207226  223190      S
## 1328  395023  368115     NC
## 2494  214497  216162      S
## 2260   20777   26898     NE
## 318    69405   73603      S
## 2114  300829  318542      S
## 3048   47366   48770      S
## 461   121588  131334      S
## 3020   19956   21369      S
## 2357  560057  575695     NC
## 1401  201670  200323     NC
## 1568   78230   91427      S
## 738   392639  415755     NC
## 377   213943  216594      S
## 2542  571684  655499      S
## 404   168593  163114      S
## 1728  777675  816265     NC
## 886   324063  340899     NC
## 2978  265731  281891     NC
## 1388  163076  178651     NC
## 2620  330173  312129      S
## 2502  337351  347215      S
## 1185  123932  137529      S
## 2244   88982   99920     NE
## 2981  270930  291181     NC
## 1848  297326  332862     NC
## 1153   34235   42562     NE
## 1875   46056   47923     NE
## 1246   18047   18555     NC
## 577   321950  322206     NC
## 1754  531643  557568     NC
## 1646   53902   50446      S
## 2154  390957  388174      S
## 2872    2358    3374      S
## 1529  262371  277137      S
## 1542   93180  123870      S
## 1798  345739  359241     NC
## 1587 1730537 1646324      W
## 1501  294547  260026      S
## 304    86026   83994      S
## 2342 1243168 1104452     NC
## 1205   16099   16140     NC
## 2709  536507  474001      S
## 2683 1695484 1890612      S
## 2200   34292   35230      W
## 1862  217228  241886     NC
## 584   347599  342938     NC
## 759   488215  487699     NC
## 1873   25439   26574     NE
## 2317  128124  124284      S
## 1295  113422  132863     NC
## 932   547369  545417     NC
## 72     56680   57923      S
## 2630  698832  653556      S
## 861   162244  165339     NC
## 845   121710  132099     NC
## 2593  313952  330751      S
## 1287  168073  178100     NC
## 778   227711  221878     NC
## 2977  282405  315416     NC
## 1142   61883   65151      S
## 2285    9631   10356     NE
## 251   878447  996785      W
## 40    191810  207817      S
## 2366  502469  490333     NC
## 1861 1005877 1122369     NC
## 1275    3786    4159     NC
## 2091   19088   19808     NC
## 899   532890  538449     NC
## 226   796892  855503      W
## 2776  105576  101622      W
## 2486   49452   53305      S
## 1465  204171  218426     NC
## 1527   95736   96008      S
## 602   542855  543881     NC
## 410   184137  179393      S
## 696   431415  459120     NC
## 894   512728  503589     NC
## 2465  257000  258567      S
## 917   485656  469908     NC
## 704   453944  485142     NC
## 1485  289729  290980     NC
## 2564  426189  392585      S
## 2303  156853  155717      S
## 1156   74484   82864     NE
## 2854   24924   29758      S
## 373    62983   68705      S
## 1979  195626  212804     NE
## 74    151325  154580      S
## 1872   20910   21479     NE
## 2339 1026353  992938     NC
## 1000  147154  155594      S
## 2875   43332   39358      S
## 2846  297064  300699      S
## 1126  210570  196324      S
## 2794   51604   59527      S
## 2670   30268   64047      S
## 927   441417  436761     NC
# Check the dimension
(dim(agpop_sampled))
## [1] 300   3
# Create an estimate for the population mean 
# using the sample mean
# Sample mean for ACRES92 is 351725.5
# (Reference) Population mean for ACRES92 = 309900.4
(ACRES92_samplemean <- mean(agpop_sampled$ACRES92))
## [1] 351725.5
# Estimated population mean for ACRES92 
# based from simple random sampling is 351725.5

# Create an estimate for the population total 
# using the product of sample mean and population size
# Sample mean for ACRES92 is 351725.5
# Population size is 3044
# Estimated population total is 1070652381
# (Reference) Population total for ACRES92 is 943336889
(ACRES92_totalestimate <- N*ACRES92_samplemean)
## [1] 1070652381
# Estimated population total for ACRES92 
# based from simple random sampling is 1070652381

Item 4

##############################################
############       ITEM 4        #############
##############################################
# Using set.seed(last 5 digits of your std no + 10) 
# obtain a sample of size 21 from the Northeast stratum.
# Using set.seed(last 5 digits of your std no + 11) 
# obtain a sample of size 103 from the NorthCentral stratum.
# Using set.seed(last 5 digits of your std no + 12) 
# obtain a sample of size 135 from the South stratum.
# Using set.seed(last 5 digits of your std no + 13) 
# obtain a sample of size 41 from the West stratum.
##############################################

# Set the seed numbers
(seedSTR1 <- seedSRS0+10)
## [1] 89186
(seedSTR2 <- seedSRS0+11)
## [1] 89187
(seedSTR3 <- seedSRS0+12)
## [1] 89188
(seedSTR4 <- seedSRS0+13)
## [1] 89189
# Specify the sample size for each stratum
(n.NEregion <- 21)
## [1] 21
(n.NCregion <- 103)
## [1] 103
(n.Sregion <- 135)
## [1] 135
(n.Wregion <- 41)
## [1] 41
# Specify the overall sample size
(nSTR <- n.NCregion + n.NEregion + n.Sregion + n.Wregion)
## [1] 300
# Generate the sample indices for each stratum
set.seed(seedSTR1)
(sampleindices10.NEregion <- sample(N.NEregion,n.NEregion))
##  [1] 124 188 168  23  89 152  49  99 135 192  78  69 109  65  94   3  83
## [18]  80 207 115  51
set.seed(seedSTR2)
(sampleindices11.NCregion <- sample(N.NCregion,n.NCregion))
##   [1]  848  308   77  580  885  325    1  621  506  856  521  924  425  768
##  [15]  702   81  520  503  896  781   11  245  744  653   85   22   70  501
##  [29]  183  117  562  648  859   12  498  731  405  926  552  448  107  280
##  [43]  843  996  283  778  202  181   89  791  684  886 1038  903  524  813
##  [57]  626  983  256  356  590  204  884  144  658  741   99   82  920  324
##  [71]  664  398  904  988  888  737  746  959  701  284  269  175  923   26
##  [85] 1044  382  366  109  681    3  429  846  242  322  258  750  166  292
##  [99]   20  860  705  331  879
set.seed(seedSTR3)
(sampleindices12.Sregion <- sample(N.Sregion,n.Sregion))
##   [1]  676   13  353   73  818  180 1068  240 1035  537  584  603  115  239
##  [15] 1351  471   87 1205  155  454  764  810  400   58 1275   43  964  425
##  [29]  267 1072 1140 1065  811  461 1227 1025 1053  882 1255  666  612 1023
##  [43]  307  976  159 1217   77 1317  325 1273  971  542  199 1151  462  877
##  [57]   17  529  731 1368  743  873    4  137  942  778  198 1132  663  301
##  [71]  627  727  692   39  162  470  720 1294 1064 1168 1219 1036 1344 1345
##  [85]  984  222  230 1320 1106 1104    9 1318 1127  455 1034  559   76 1091
##  [99]  979 1276  849  615  838  601  786  365 1049 1230  300  699 1154 1209
## [113]  274 1098   70  100  156  223 1346   22  771  499  546   75  783  841
## [127]  656   96  296 1270  233  777 1015 1129  256
set.seed(seedSTR4)
(sampleindices13.Wregion <- sample(N.Wregion,n.Wregion))
##  [1] 199 348 240 285 414 201 181 394 246  20  35 398 314 178  49 298 361
## [18] 308 411 264   6 130 121 334  66 335 376 393 138 378 172  26 211 282
## [35]  90 168 135 253 102 144 227
# Generate the actual samples
(NEregion_sampled10 <- NEregion[sampleindices10.NEregion,])
##      ACRES92 ACRES87 REGION
## 2011  174627  191309     NE
## 2278  203026  218906     NE
## 2257   39561   44930     NE
## 1188   62242   69551     NE
## 1974  163072  175803     NE
## 2241  106390  116231     NE
## 1882   29606   29423     NE
## 1984  135494  146537     NE
## 2223  310672  338776     NE
## 2282  252052  278239     NE
## 1962  158392  172734     NE
## 1902   87638   87583     NE
## 1996     831    1107     NE
## 1898   98256   95265     NE
## 1979  195626  212804     NE
## 286    86581   95321     NE
## 1967  145679  166121     NE
## 1964  138620  148153     NE
## 2885  149503  168175     NE
## 2002  115071  126320     NE
## 1884   97186  103224     NE
(NCregion_sampled11 <- NCregion[sampleindices11.NCregion,])
##      ACRES92 ACRES87 REGION
## 2036   88899   90106     NC
## 876   407464  397383     NC
## 601   229818  238256     NC
## 1387  339372  324379     NC
## 2073  164607  165764     NC
## 893   671506  676575     NC
## 525   328970  353365     NC
## 1428  332910  317276     NC
## 1313   79183   91078     NC
## 2044  127867  137708     NC
## 1328  395023  368115     NC
## 2343  417697  425661     NC
## 1230    5965    5936     NC
## 1813 1069778 1074776     NC
## 1747  723816  758474     NC
## 605   364172  359677     NC
## 1327  255453  253044     NC
## 1310  366534  384001     NC
## 2084  160734  168992     NC
## 1826  326831  338329     NC
## 535   341923  358798     NC
## 813   187549  191358     NC
## 1789  270005  290941     NC
## 1460  228936  246348     NC
## 609   331211  327081     NC
## 546   456954  450742     NC
## 594   219832  233026     NC
## 1308  414710  427986     NC
## 751   446750  493253     NC
## 685   176012  178175     NC
## 1369  249731  252824     NC
## 1455  323465  336976     NC
## 2047  248400  264054     NC
## 536   315448  328114     NC
## 1305  221193  219920     NC
## 1776 1160916 1187041     NC
## 1210   14104   13902     NC
## 2345  534829  540538     NC
## 1359  643762  671895     NC
## 1254   48029   46747     NC
## 675   238906  259634     NC
## 848   257351  247010     NC
## 2031  223216  222057     NC
## 2944   70547   74561     NC
## 851    80958   85852     NC
## 1823 1387740 1415617     NC
## 770   197724  205872     NC
## 749   264140  279859     NC
## 613   241422  244939     NC
## 1836  330369  293257     NC
## 1729  818893  799317     NC
## 2074  187718  194218     NC
## 2988  207128  209508     NC
## 2091   19088   19808     NC
## 1331  744710  819664     NC
## 1858  314949  339349     NC
## 1433  199292  201016     NC
## 2931  350866  374522     NC
## 824   139523  145490     NC
## 924   323769  327193     NC
## 1397  130358  140126     NC
## 772   165091  175883     NC
## 2072  113892  112208     NC
## 712   203590  227961     NC
## 1465  204171  218426     NC
## 1786  296164  293720     NC
## 623   353683  344010     NC
## 606   233217  230461     NC
## 2339 1026353  992938     NC
## 892   164081  170339     NC
## 1471  165225  156208     NC
## 966    22553   23936     NC
## 2092  120519  122492     NC
## 2936  162205  168831     NC
## 2076  106573  105390     NC
## 1782  407678  411712     NC
## 1791  296016  338390     NC
## 2378  485748  468868     NC
## 1746  688468  724825     NC
## 852   119318  127753     NC
## 837   236436  244226     NC
## 743    67998   75234     NC
## 2342 1243168 1104452     NC
## 550   275319  266999     NC
## 2995  147207  156317     NC
## 950   227349  221098     NC
## 934   449151  486999     NC
## 677   571807  594227     NC
## 1726  594587  626589     NC
## 527   321728  321226     NC
## 1234   29161   31751     NC
## 2034  196759  206905     NC
## 810   139638  139792     NC
## 890   671223  674986     NC
## 826   184118  197875     NC
## 1795  772453  765900     NC
## 734   187039  203136     NC
## 860   285169  292938     NC
## 544   236409  229423     NC
## 2048  113329  118939     NC
## 1750 1048701 1047851     NC
## 899   532890  538449     NC
## 2067   87036   85076     NC
(Sregion_sampled12 <-  Sregion[sampleindices12.Sregion,])
##      ACRES92 ACRES87 REGION
## 1648   93970  107269      S
## 18     61426   94506      S
## 508    55779   65220      S
## 78     30196   31795      S
## 2168  309614  267016      S
## 333    11738   17507      S
## 2593  313952  330751      S
## 395   178861  178875      S
## 2559  599637  588433      S
## 1138   40181   57922      S
## 1499   68663   74002      S
## 1518   89168   97908      S
## 120   219444  234605      S
## 394    10192   13420      S
## 3036  178160  184323      S
## 1072  229838  224123      S
## 92     20589   18918      S
## 2731  242901  276750      S
## 307    83681   83061      S
## 1055  117868  118240      S
## 2114  300829  318542      S
## 2160  207118  215865      S
## 1001  193859  204660      S
## 63     78176   89109      S
## 2832   85600   83709      S
## 48    199714  207753      S
## 2488  165309  165266      S
## 1026    3224    3780      S
## 422    25376   27498      S
## 2597  686578  956997      S
## 2666   73948   75350      S
## 2590  443027  393949      S
## 2161  282211  284665      S
## 1062  127403  135728      S
## 2782   90296   93860      S
## 2549 1584367 1606076      S
## 2578  102229   98924      S
## 2406   30299   34850      S
## 2812   73097   71550      S
## 1637   31671   34833      S
## 1527   95736   96008      S
## 2547 2001152 1854660      S
## 462   205573  223620      S
## 2500  500665  482017      S
## 311    57179   65426      S
## 2743  461127  402967      S
## 82     98919  114391      S
## 2875   43332   39358      S
## 480    12733   14377      S
## 2830  195476  206601      S
## 2495  352488  350886      S
## 1143  316691  333377      S
## 352   151242  166766      S
## 2677  195147  201728      S
## 1063    4469    3271      S
## 2401  213603  221058      S
## 22    138135  145104      S
## 1130    6166    5884      S
## 1704  130879  137426      S
## 3053   35836   36627      S
## 1716   67716   71442      S
## 2331   55992   56998      S
## 9      48022   50818      S
## 142    31190   34580      S
## 2466  105519  110079      S
## 2128  566152  547352      S
## 351    79270   81667      S
## 2658  487573  501761      S
## 1634  127760  130650      S
## 456     8003    5071      S
## 1542   93180  123870      S
## 1700   23140   26073      S
## 1665  112291  117207      S
## 44    201892  199960      S
## 315    70987   87500      S
## 1071  154082  164293      S
## 1693   67491   81108      S
## 2852   78977   77112      S
## 2589  560355  582208      S
## 2694  572607  576671      S
## 2745  344667  348460      S
## 2560  801159  996776      S
## 3028   56555   49353      S
## 3029   74760   76343      S
## 2508  416631  422998      S
## 377   213943  216594      S
## 385    21697   25758      S
## 3003    2531    2635      S
## 2632  576893  534150      S
## 2629  436040  409706      S
## 14    109555  102153      S
## 3001   76080   83174      S
## 2653  512473  503635      S
## 1056  191002  202339      S
## 2558  677308  695478      S
## 1174  222768  236350      S
## 81    269122  320847      S
## 2616 1524636 1532081      S
## 2503  432939  432697      S
## 2833  100602  106419      S
## 2307   55712   57293      S
## 1530   98914  103596      S
## 2296   90995   92792      S
## 1516   76673   78932      S
## 2136  405271  394472      S
## 520   200061  198012      S
## 2574  128533  118725      S
## 2786   47010   53523      S
## 455    33785   38527      S
## 1672   56693   66292      S
## 2680 2891640 2918048      S
## 2735  644730  685935      S
## 429    36074   39886      S
## 2623  386991  361425      S
## 75     92708  103034      S
## 105   183895  173516      S
## 308   334623  351402      S
## 378   166511  202944      S
## 3031   54622   52964      S
## 27    196859  193771      S
## 2121  336285  279924      S
## 1100   63674   63548      S
## 1147   38566   42488      S
## 80    246184  240838      S
## 2133  268038  268553      S
## 2299   94193   95757      S
## 1627   52974   57431      S
## 101   168848  182876      S
## 451    32657   36282      S
## 2827   59326   63576      S
## 388    52651   55316      S
## 2127  419760  404416      S
## 2539  549167  559698      S
## 2655  562612  578993      S
## 411    16362   13745      S
(Wregion_sampled13 <-  Wregion[sampleindices13.Wregion,])
##      ACRES92 ACRES87 REGION
## 1583 2232575 2143210      W
## 2773  450315  493902      W
## 1624  490988  516382      W
## 1950  710618  880792      W
## 3078 1484583 1546633      W
## 1585  699409  731603      W
## 663     4428    5148      W
## 3058 2704163 2893716      W
## 1908  924678  990255      W
## 162   229365  272399      W
## 177  2839531 3037068      W
## 3062 2415873 2464688      W
## 2206  167880  176178      W
## 660   752032  716637      W
## 191    72471   56179      W
## 2190  766373  763612      W
## 2898  918033  987885      W
## 2200   34292   35230      W
## 3075   62307   72197      W
## 1927 1896131 1857223      W
## 148  5785707 5779528      W
## 275   462086  472194      W
## 265   633279  731609      W
## 2759  434183  483118      W
## 209   647446  669385      W
## 2760  332686  273876      W
## 2913 1291118 1339306      W
## 3057  441321  467739      W
## 521   926607 1007287      W
## 2915   55360   62578      W
## 654   211039  222624      W
## 168   450236  456266      W
## 1595  951780  934149      W
## 1945  189223  209805      W
## 233   423785  408649      W
## 650   207552  205315      W
## 281  1333577 1391208      W
## 1915  843401 1226048      W
## 246   177333  225220      W
## 626   325338  358189      W
## 1611 1197028 1194869      W

Item 5

##############################################
############       ITEM 5        #############
##############################################
# Estimate the population mean and total 
# of ACRES92 using a ratio estimator with 
# ACRES87 as auxiliary variable. 
# (see p. 119, equation (42))
##############################################

# Generate the sample means for ACRES92 and ACRES87
# Sample mean for ACRES92 is 351725.5
(ACRES92_samplemean <- mean(agpop_sampled$ACRES92))
## [1] 351725.5
# Sample mean for ACRES87 is 358120.2
(ACRES87_samplemean <- mean(agpop_sampled$ACRES87))
## [1] 358120.2
# Create an estimate for the population mean of ACRES92 
# using ACRES87 as auxiliary variable
# Estimated population mean for ACRES92 
# using ACRES87 as auxiliary variable is 310450.4
# (Reference) actual ACRES92 population mean is 309900.4
(ACRES92_estimatedmeanusingACRES87 <- 
    (ACRES92_samplemean/ACRES87_samplemean)*ACRES87_popmean)
## [1] 310450.4
# Estimated population mean for ACRES92 
# based from auxiliary variable ACRES87 is 310450.4

# Generate the sample total for ACRES92 and ACRES87
# Sample total for ACRES92 is 105517646
(ACRES92_sampletotal <- sum(agpop_sampled$ACRES92))
## [1] 105517646
# Sample total for ACRES87 is 107436057
(ACRES87_sampletotal <- sum(agpop_sampled$ACRES87))
## [1] 107436057
# Create an estimate for the population total of ACRES92 
# using ACRES87 as auxiliary variable
# Estimated population total for ACRES92 
# using ACRES87 as auxiliary variable is 945011015
# (Reference) actual ACRES92 population total is 943336889
(ACRES92_estimatedtotalusingACRES87 <- 
    (ACRES92_sampletotal/ACRES87_sampletotal)*ACRES87_poptotal)
## [1] 945011015
# Estimated population total for ACRES92 
# based from auxiliary variable ACRES87 is 945011015

Item 6

##############################################
############       ITEM 6        #############
##############################################
# Estimate the population total
# using a combined ratio estimator.
# (see p.144 and equation 3.2 from p.78)
##############################################

# Gathering all needed formula components

# Population size N per stratum
# North East region stratum population size = 211
(N.NEregion <- nrow(NEregion))
## [1] 211
# North Central region stratum population size = 1049
(N.NCregion <- nrow(NCregion))
## [1] 1049
# South region stratum population size = 1370
(N.Sregion <- nrow(Sregion))
## [1] 1370
# West region stratum population size = 414
(N.Wregion <- nrow(Wregion))
## [1] 414
# ACRES92 sample mean per stratum
# North East region stratum sample mean for ACRES92 = 130958.3
(ACRES92samplemean.NEregion <- mean(NEregion_sampled10$ACRES92))
## [1] 130958.3
# North Central region stratum sample mean for ACRES92 = 333711.1
(ACRES92samplemean.NCregion <- mean(NCregion_sampled11$ACRES92))
## [1] 333711.1
# South region stratum sample mean for ACRES92 = 242028.8
(ACRES92samplemean.Sregion <- mean(Sregion_sampled12$ACRES92))
## [1] 242028.8
# West region stratum sample mean for ACRES92 = 906734.9
(ACRES92samplemean.Wregion <- mean(Wregion_sampled13$ACRES92))
## [1] 906734.9
# ACRES87 sample mean per stratum
# North East region stratum sample mean for ACRES87 = 142214.9
(ACRES87samplemean.NEregion <- mean(NEregion_sampled10$ACRES87))
## [1] 142214.9
# North Central region stratum sample mean for ACRES87 = 339147.8
(ACRES87samplemean.NCregion <- mean(NCregion_sampled11$ACRES87))
## [1] 339147.8
# South region stratum sample mean for ACRES87 = 247570.8
(ACRES87samplemean.Sregion <- mean(Sregion_sampled12$ACRES87))
## [1] 247570.8
# West region stratum sample mean for ACRES87 = 945363.4
(ACRES87samplemean.Wregion <- mean(Wregion_sampled13$ACRES87))
## [1] 945363.4
# Compute for the estimated total for ACRES92 by summing up
# the products of the size and sample mean for ACRES92 per stratum
(ACRES92_estimatedtotalSTR <- 
  (N.NEregion * ACRES92samplemean.NEregion) +
  (N.NCregion * ACRES92samplemean.NCregion) +
  (N.Sregion * ACRES92samplemean.Sregion) +
  (N.Wregion * ACRES92samplemean.Wregion))
## [1] 1084662926
# The estimated total for ACRES92 using Stratified Random Sampling is 1084662926
# (Reference) actual ACRES92 population total is 943336889

# Compute for the estimated total for ACRES87 by summing up
# the products of the size and sample mean for ACRES87 per stratum
(ACRES87_estimatedtotalSTR <- 
  (N.NEregion * ACRES87samplemean.NEregion) +
  (N.NCregion * ACRES87samplemean.NCregion) +
  (N.Sregion * ACRES87samplemean.Sregion) +
  (N.Wregion * ACRES87samplemean.Wregion))
## [1] 1116325782
# The estimated total for ACRES87 using Stratified Random Sampling is 1116325782
# (Reference) actual ACRES87 population total is 962192213

# Compute for the estimated ratio by dividing the 
# estimated totals for ACRES92 and ACRES87 using Stratified Random Sampling
(ACRES92_estimatedBRatio <- ACRES92_estimatedtotalSTR/ACRES87_estimatedtotalSTR)
## [1] 0.9716365
# The estimated value for B is 0.9716365

# Compute for the estimated population total for ACRES92
# using the formula for combined ratio estimator
(ACRES92_estimatedtotalusingACRES87byCRE <- 
  ACRES92_estimatedBRatio*ACRES87_poptotal)
## [1] 934901117
# Estimated population total for ACRES92 
# based from auxiliary variable ACRES87 and
# using the combined ratio estimator method is 934901117
# (Reference) actual ACRES92 population total is 943336889

Item 7

##############################################
############       ITEM 7        #############
##############################################
# Estimate the population total
# using separate ratio estimator. 
# (see p.144)
##############################################

# Gathering all needed formula components

# ACRES87 population total per stratum
# North East region stratum population total for ACRES87 = 22025736
(ACRES87poptotal.NEregion <- sum(NEregion$ACRES87))
## [1] 22025736
# North Central region stratum population total for ACRES87 = 350433336
(ACRES87poptotal.NCregion <- sum(NCregion$ACRES87))
## [1] 350433336
# South region stratum population total for ACRES87 = 279311080
(ACRES87poptotal.Sregion <- sum(Sregion$ACRES87))
## [1] 279311080
# West region stratum population total for ACRES87 = 310422061
(ACRES87poptotal.Wregion <- sum(Wregion$ACRES87))
## [1] 310422061
# ACRES92 sample total per stratum
# North East region stratum sample total for ACRES92 = 2750125
(ACRES92sampletotal.NEregion <- sum(NEregion_sampled10$ACRES92))
## [1] 2750125
# North Central region stratum sample total for ACRES92 = 34372245
(ACRES92sampletotal.NCregion <- sum(NCregion_sampled11$ACRES92))
## [1] 34372245
# South region stratum sample total for ACRES92 = 32673894
(ACRES92sampletotal.Sregion <- sum(Sregion_sampled12$ACRES92))
## [1] 32673894
# West region stratum sample total for ACRES92 = 37176130
(ACRES92sampletotal.Wregion <- sum(Wregion_sampled13$ACRES92))
## [1] 37176130
# ACRES87 sample total per stratum
# North East region stratum sample total for ACRES87 = 2986512
(ACRES87sampletotal.NEregion <- sum(NEregion_sampled10$ACRES87))
## [1] 2986512
# North Central region stratum sample total for ACRES87 = 34932222
(ACRES87sampletotal.NCregion <- sum(NCregion_sampled11$ACRES87))
## [1] 34932222
# South region stratum sample total for ACRES87 = 33422056
(ACRES87sampletotal.Sregion <- sum(Sregion_sampled12$ACRES87))
## [1] 33422056
# West region stratum sample total for ACRES87 = 38759899
(ACRES87sampletotal.Wregion <- sum(Wregion_sampled13$ACRES87))
## [1] 38759899
# Compute for the estimated population total for ACRES92
# using the formula for separate ratio estimator
(ACRES92_estimatedtotalusingACRES87bySRE <- 
    (ACRES87poptotal.NEregion *
       (ACRES92sampletotal.NEregion / ACRES87sampletotal.NEregion)) +
    (ACRES87poptotal.NCregion *
       (ACRES92sampletotal.NCregion / ACRES87sampletotal.NCregion)) +
    (ACRES87poptotal.Sregion *
       (ACRES92sampletotal.Sregion / ACRES87sampletotal.Sregion)) +
    (ACRES87poptotal.Wregion *
       (ACRES92sampletotal.Wregion / ACRES87sampletotal.Wregion)))
## [1] 935894643
# Estimated population total for ACRES92 
# based from auxiliary variable ACRES87 and
# using the separate ratio estimator method is 935894643
# (Reference) actual ACRES92 population total is 943336889

# Create the overall summary
(EstimationMethod <- 
    c( "Actual Population",
   "Simple Random Sampling",
   "Ratio using ACRES87",
   "Combined Ratio using ACRES87",
   "Separate Ratio using ACRES87"))
## [1] "Actual Population"            "Simple Random Sampling"      
## [3] "Ratio using ACRES87"          "Combined Ratio using ACRES87"
## [5] "Separate Ratio using ACRES87"
(ACRES92PopulationTotal <- 
    c( format(round(ACRES92_poptotal),nsmall=2,scientific=FALSE),
    format(round(ACRES92_totalestimate),nsmall=2,scientific=FALSE),
    format(round(ACRES92_estimatedtotalusingACRES87),nsmall=2,scientific=FALSE),
    format(round(ACRES92_estimatedtotalusingACRES87byCRE),nsmall=2,scientific=FALSE),
    format(round(ACRES92_estimatedtotalusingACRES87bySRE),nsmall=2,scientific=FALSE)))
## [1] "943336889.00"  "1070652381.00" "945011015.00"  "934901117.00" 
## [5] "935894643.00"
(ACRES92PopulationMean <- 
    c( format(round(ACRES92_popmean),nsmall=2,scientific=FALSE),
    format(round(ACRES92_samplemean),nsmall=2,scientific=FALSE),
    format(round(ACRES92_estimatedmeanusingACRES87),nsmall=2,scientific=FALSE),
    NA,
    NA))
## [1] "309900.00" "351725.00" "310450.00" NA          NA
(ACRES92Summary <- 
    as.data.frame(cbind(EstimationMethod,
    ACRES92PopulationTotal,
    ACRES92PopulationMean)))
##               EstimationMethod ACRES92PopulationTotal
## 1            Actual Population           943336889.00
## 2       Simple Random Sampling          1070652381.00
## 3          Ratio using ACRES87           945011015.00
## 4 Combined Ratio using ACRES87           934901117.00
## 5 Separate Ratio using ACRES87           935894643.00
##   ACRES92PopulationMean
## 1             309900.00
## 2             351725.00
## 3             310450.00
## 4                  <NA>
## 5                  <NA>