x<-0:20             # generate an integer sequence from 0 to 20
p<-dbinom(x,size=20,prob=1/4)   # p is a prob vector, p=Pr(X=x)
round(p,digits=4)           # display the vector p
##  [1] 0.0032 0.0211 0.0669 0.1339 0.1897 0.2023 0.1686 0.1124 0.0609 0.0271
## [11] 0.0099 0.0030 0.0008 0.0002 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
## [21] 0.0000
1-pbinom(8,size=20,prob=1/4)    # Pr{X>8} = 1 – Pr{X<=8}
## [1] 0.04092517
1-sum(p[1:9])   # Pr{X>8} = 1- Pr{X<=8}
## [1] 0.04092517
 (q<-seq(0,1,0.1))              # create and display q
##  [1] 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
 qbinom(q,size=20,prob=1/4)     # quantiles from bin(n,p) corresponds to q
##  [1]  0  3  3  4  4  5  5  6  7  8 20
round(cumsum(p),digits=4)
##  [1] 0.0032 0.0243 0.0913 0.2252 0.4148 0.6172 0.7858 0.8982 0.9591 0.9861
## [11] 0.9961 0.9991 0.9998 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000
## [21] 1.0000
set.seed(123)           # set initial seed
x<-runif(500,0,20)
x
##   [1]  5.751550402 15.766102709  8.179538436 17.660348080 18.809345686
##   [6]  0.911129988 10.562109761 17.848380888 11.028700289  9.132294706
##  [11] 19.136666907  9.066683124 13.551412709 11.452668039  2.058493653
##  [16] 17.996499408  4.921754687  0.841190671  6.558414386 19.090072983
##  [21] 17.790786321 13.856068123 12.810136275 19.885395532 13.114115982
##  [26] 14.170609363 10.881320494 11.882840409  5.783194746  2.942272946
##  [31] 19.260484651 18.045980902 13.814105568 15.909348354  0.492273690
##  [36]  9.555919422 15.169190750  4.328158717  6.363620153  4.632515707
##  [41]  2.856000448  8.290926716  8.274486526  7.376909018  3.048894955
##  [46]  2.776121269  4.660681989  9.319249005  5.319452807 17.156554307
##  [51]  0.916623333  8.844001484 15.978496913  2.437985200 11.218959675
##  [56]  4.130627792  2.550633005 15.066157286 17.900907183  7.489255518
##  [61] 13.302303893  1.896813218  7.679392756  5.487672891 16.292800778
##  [66]  8.970326828 16.201287061 16.247790190 15.886846422  8.796633752
##  [71] 15.089503173 12.584422631 14.203648027  0.012495467  9.506331482
##  [76]  4.402377703  7.596330754 12.255420065  7.035958185  2.222708487
##  [81]  4.872389454 13.361111749  8.352935594 15.763916681  2.057292885
##  [86]  8.697854830 19.699139600 17.861022288 17.729381216  3.501053005
##  [91]  2.613913831 13.062038501  6.870329445 13.135162559  6.407464850
##  [96]  3.753822385 15.645886026  1.871899734  9.335580831 10.230109198
## [101] 11.999779185  6.656470806  9.772260673 19.089476550  9.658047943
## [106] 17.807004442 18.288763738 12.174699646  8.213795531  2.941893819
## [111] 18.705996065  6.024577999  1.214411431 18.954538801 14.411925469
## [116]  2.845885912 10.985693121 19.081824771 11.709667062  8.090205635
## [121] 12.957869587  6.396412342  6.154400217  4.395352625  7.389777317
## [126] 19.684384069  3.084046016  1.820879998  2.838138156 13.800142030
## [131] 12.385129668 17.827882343 13.459981852 14.741554759 10.422714516
## [136] 13.196768994 16.436109203 15.725631034 19.596438347  8.788630725
## [141]  6.234044041  8.189499052  0.209342237  3.676990480 16.854586378
## [146]  4.623235641  4.781999113  1.533823307  4.914473561 14.642704111
## [151] 16.949063302  9.950545342  7.758180597  4.928979883  2.221929226
## [156]  7.799888705 11.438706280  4.337855256  8.895360040  4.359813374
## [161] 10.045991265  7.078091437 12.999703176  7.494279132  7.108907616
## [166] 10.673758909 14.806687208  4.422058756  8.254922372  5.313733737
## [171] 12.599461069  3.676569816 17.272882229 14.931360083 13.365692995
## [176] 12.360357465  7.444761205 10.596713717 17.493646857 11.635001996
## [181] 16.795355296  6.248963298 14.165806444  5.300356122 11.886863881
## [186]  9.625796010  5.300654629 11.291808696 18.263764461 18.037487790
## [191]  5.483332430  6.429655128 19.712817688 12.399866204 18.746281783
## [196]  9.330654046  8.136651865 13.184606484  3.046932337 11.457341164
## [201]  4.774520537 19.247178729 12.027314520 10.300594545  8.051466844
## [206] 17.604930825  7.281837296  5.764785614  3.412904702  3.443434928
## [211]  9.640852110  5.059298570  4.325095792 13.487527762  0.953272549
## [216] 14.017061749  7.037772769  8.178879959 16.419026479 18.377146963
## [221]  5.650566602 19.222095874 14.567888565 13.727501640  1.056878855
## [226]  7.904402693  9.556907597 11.205065274 13.965231897 18.313670768
## [231] 12.367024547  8.568430175 10.841607344  1.169569772  5.217137141
## [236]  7.943039066  3.954894734 16.638551257  3.057744456 16.068370841
## [241] 10.936523131 13.246352840  3.433969878 12.661107196  6.237394935
## [246] 14.491086928  7.978796493 19.387128223 19.347967412 14.534050780
## [251]  5.144334929  4.435758693 11.860913034  5.350428643 10.621407977
## [256] 15.705833426  3.361216211  8.087983620  9.431525553 17.362136138
## [261] 18.514159117 17.639551186 13.483736850 19.003339587 10.328897885
## [266] 11.530380426  6.726624118  6.946492628  0.400486011 10.056260913
## [271] 17.420868273  0.126015679  1.441142480  3.284224500 15.406681485
## [276] 14.703686116 19.437512713  9.329447537  1.487690266 12.976362486
## [281] 15.171863390  2.742121620  7.931691892  4.499706584  1.159171211
## [286]  7.917853766  1.298566000  4.517728658  1.092582182 13.405640791
## [291]  5.954835652  2.014431646  1.438081944 17.608811376 15.084948041
## [296] 16.332117752 19.642807473  2.071992899  1.980836587 15.976632223
## [301] 15.691505331  0.188598102 15.581317656 14.587813038 12.602637056
## [306]  9.618216599  3.132737027  0.164310397  9.049167885  9.845866575
## [311]  7.791742231  9.293318838 14.265580014  1.106038527  7.095661950
## [316] 16.056245458 16.714176740  4.754988099  7.079722052 17.137708403
## [321] 17.075267476  5.917909108  2.940966492 14.079841226  2.076133764
## [326]  0.674555460 19.988090559  0.697496082  6.767825675 18.301275233
## [331] 12.344705393  5.725706974 14.755948060 16.681086184  6.285415608
## [336]  9.851330956 13.947475324 12.829247080 12.878458300 19.557068096
## [341]  8.294706689  2.388095600 10.520593203  4.501467017  9.728235281
## [346]  7.404295970 19.667003616  7.766382303  4.584896807 12.465950926
## [351]  2.730803941 19.349389886 10.301436158  3.261406585 12.438045903
## [356] 19.719083305 13.375430349  8.378317938  6.466899863 16.705106399
## [361]  2.876340873  3.856318938 17.934773653  6.162391086  7.266010870
## [366] 15.678929575  3.867573598  0.355316238  8.132157326  9.663353385
## [371]  8.436899004  6.856176034 17.329666293  9.102161019 10.675297473
## [376] 19.276866638 15.491830842  4.177526971  6.175736655 19.426849005
## [381] 11.698001870 15.216472507  7.454187889 15.383878225 10.753543661
## [386] 18.279908993  3.705928838  5.644368348  1.899248264  4.209741582
## [391] 19.541979926  5.926043508 14.519660538 15.713756685  2.108354922
## [396]  4.791892581  5.410897448  2.021169881  2.358276825 19.824731117
## [401] 19.721085946  2.741349428 18.106191633 11.526036751  7.908977182
## [406]  8.996049683 14.130038023  1.650054916  6.786251604 13.615751024
## [411]  6.338984962 16.631371961  4.303441653  9.958978724  5.520993453
## [416]  3.840466375 19.012425281  6.434510755  9.569127676  0.559851439
## [421] 10.949189360 12.884804411 11.925270893  6.438747514 17.822286249
## [426] 12.525138948  6.058098306  7.764093275  3.209501849 17.251037951
## [431] 19.062024276 11.272893669  6.590948268 19.932344374  4.696393516
## [436] 12.253439305  2.163570588  9.740651399  1.988916467  3.223315254
## [441]  5.659857416 11.677446719 14.634153177  3.310418222 17.329355264
## [446] 14.171482744 15.207990725  2.941682171  7.161139268 13.466649628
## [451] 10.476452033  6.996035855  4.810614032  1.163835926  4.732394842
## [456] 17.801558264 16.236548321 14.950326444  3.098234516  2.494841772
## [461] 19.494516170  8.722599922  9.280332536  3.305961625 11.698731147
## [466]  5.415560389  4.601938408 13.824156630  5.657047993 16.207961324
## [471]  1.878332142 16.440601423  8.548565614 15.117745195 13.247710131
## [476]  8.890547939 12.542923689  0.009306981  4.344870280 14.097444913
## [481]  4.303329764 16.278674426  6.155277486 13.754853713 18.653621580
## [486]  2.315593297  2.554113758 13.564477148  8.578971918 16.688019559
## [491] 19.428761336  1.409779554  9.195703864 14.031702369  1.738803359
## [496] 19.858880322  5.061979881  0.990768713 13.726498936 15.738547053
y<-matrix(x,ncol=10)
y
##             [,1]        [,2]       [,3]      [,4]       [,5]       [,6]
##  [1,]  5.7515504  0.91662333 11.9997792 16.949063  4.7745205  5.1443349
##  [2,] 15.7661027  8.84400148  6.6564708  9.950545 19.2471787  4.4357587
##  [3,]  8.1795384 15.97849691  9.7722607  7.758181 12.0273145 11.8609130
##  [4,] 17.6603481  2.43798520 19.0894765  4.928980 10.3005945  5.3504286
##  [5,] 18.8093457 11.21895968  9.6580479  2.221929  8.0514668 10.6214080
##  [6,]  0.9111300  4.13062779 17.8070044  7.799889 17.6049308 15.7058334
##  [7,] 10.5621098  2.55063300 18.2887637 11.438706  7.2818373  3.3612162
##  [8,] 17.8483809 15.06615729 12.1746996  4.337855  5.7647856  8.0879836
##  [9,] 11.0287003 17.90090718  8.2137955  8.895360  3.4129047  9.4315256
## [10,]  9.1322947  7.48925552  2.9418938  4.359813  3.4434349 17.3621361
## [11,] 19.1366669 13.30230389 18.7059961 10.045991  9.6408521 18.5141591
## [12,]  9.0666831  1.89681322  6.0245780  7.078091  5.0592986 17.6395512
## [13,] 13.5514127  7.67939276  1.2144114 12.999703  4.3250958 13.4837369
## [14,] 11.4526680  5.48767289 18.9545388  7.494279 13.4875278 19.0033396
## [15,]  2.0584937 16.29280078 14.4119255  7.108908  0.9532725 10.3288979
## [16,] 17.9964994  8.97032683  2.8458859 10.673759 14.0170617 11.5303804
## [17,]  4.9217547 16.20128706 10.9856931 14.806687  7.0377728  6.7266241
## [18,]  0.8411907 16.24779019 19.0818248  4.422059  8.1788800  6.9464926
## [19,]  6.5584144 15.88684642 11.7096671  8.254922 16.4190265  0.4004860
## [20,] 19.0900730  8.79663375  8.0902056  5.313734 18.3771470 10.0562609
## [21,] 17.7907863 15.08950317 12.9578696 12.599461  5.6505666 17.4208683
## [22,] 13.8560681 12.58442263  6.3964123  3.676570 19.2220959  0.1260157
## [23,] 12.8101363 14.20364803  6.1544002 17.272882 14.5678886  1.4411425
## [24,] 19.8853955  0.01249547  4.3953526 14.931360 13.7275016  3.2842245
## [25,] 13.1141160  9.50633148  7.3897773 13.365693  1.0568789 15.4066815
## [26,] 14.1706094  4.40237770 19.6843841 12.360357  7.9044027 14.7036861
## [27,] 10.8813205  7.59633075  3.0840460  7.444761  9.5569076 19.4375127
## [28,] 11.8828404 12.25542007  1.8208800 10.596714 11.2050653  9.3294475
## [29,]  5.7831947  7.03595818  2.8381382 17.493647 13.9652319  1.4876903
## [30,]  2.9422729  2.22270849 13.8001420 11.635002 18.3136708 12.9763625
## [31,] 19.2604847  4.87238945 12.3851297 16.795355 12.3670245 15.1718634
## [32,] 18.0459809 13.36111175 17.8278823  6.248963  8.5684302  2.7421216
## [33,] 13.8141056  8.35293559 13.4599819 14.165806 10.8416073  7.9316919
## [34,] 15.9093484 15.76391668 14.7415548  5.300356  1.1695698  4.4997066
## [35,]  0.4922737  2.05729289 10.4227145 11.886864  5.2171371  1.1591712
## [36,]  9.5559194  8.69785483 13.1967690  9.625796  7.9430391  7.9178538
## [37,] 15.1691908 19.69913960 16.4361092  5.300655  3.9548947  1.2985660
## [38,]  4.3281587 17.86102229 15.7256310 11.291809 16.6385513  4.5177287
## [39,]  6.3636202 17.72938122 19.5964383 18.263764  3.0577445  1.0925822
## [40,]  4.6325157  3.50105301  8.7886307 18.037488 16.0683708 13.4056408
## [41,]  2.8560004  2.61391383  6.2340440  5.483332 10.9365231  5.9548357
## [42,]  8.2909267 13.06203850  8.1894991  6.429655 13.2463528  2.0144316
## [43,]  8.2744865  6.87032945  0.2093422 19.712818  3.4339699  1.4380819
## [44,]  7.3769090 13.13516256  3.6769905 12.399866 12.6611072 17.6088114
## [45,]  3.0488950  6.40746485 16.8545864 18.746282  6.2373949 15.0849480
## [46,]  2.7761213  3.75382239  4.6232356  9.330654 14.4910869 16.3321178
## [47,]  4.6606820 15.64588603  4.7819991  8.136652  7.9787965 19.6428075
## [48,]  9.3192490  1.87189973  1.5338233 13.184606 19.3871282  2.0719929
## [49,]  5.3194528  9.33558083  4.9144736  3.046932 19.3479674  1.9808366
## [50,] 17.1565543 10.23010920 14.6427041 11.457341 14.5340508 15.9766322
##             [,7]       [,8]       [,9]        [,10]
##  [1,] 15.6915053  2.7308039 19.7210859 10.476452033
##  [2,]  0.1885981 19.3493899  2.7413494  6.996035855
##  [3,] 15.5813177 10.3014362 18.1061916  4.810614032
##  [4,] 14.5878130  3.2614066 11.5260368  1.163835926
##  [5,] 12.6026371 12.4380459  7.9089772  4.732394842
##  [6,]  9.6182166 19.7190833  8.9960497 17.801558264
##  [7,]  3.1327370 13.3754303 14.1300380 16.236548321
##  [8,]  0.1643104  8.3783179  1.6500549 14.950326444
##  [9,]  9.0491679  6.4668999  6.7862516  3.098234516
## [10,]  9.8458666 16.7051064 13.6157510  2.494841772
## [11,]  7.7917422  2.8763409  6.3389850 19.494516170
## [12,]  9.2933188  3.8563189 16.6313720  8.722599922
## [13,] 14.2655800 17.9347737  4.3034417  9.280332536
## [14,]  1.1060385  6.1623911  9.9589787  3.305961625
## [15,]  7.0956620  7.2660109  5.5209935 11.698731147
## [16,] 16.0562455 15.6789296  3.8404664  5.415560389
## [17,] 16.7141767  3.8675736 19.0124253  4.601938408
## [18,]  4.7549881  0.3553162  6.4345108 13.824156630
## [19,]  7.0797221  8.1321573  9.5691277  5.657047993
## [20,] 17.1377084  9.6633534  0.5598514 16.207961324
## [21,] 17.0752675  8.4368990 10.9491894  1.878332142
## [22,]  5.9179091  6.8561760 12.8848044 16.440601423
## [23,]  2.9409665 17.3296663 11.9252709  8.548565614
## [24,] 14.0798412  9.1021610  6.4387475 15.117745195
## [25,]  2.0761338 10.6752975 17.8222862 13.247710131
## [26,]  0.6745555 19.2768666 12.5251389  8.890547939
## [27,] 19.9880906 15.4918308  6.0580983 12.542923689
## [28,]  0.6974961  4.1775270  7.7640933  0.009306981
## [29,]  6.7678257  6.1757367  3.2095018  4.344870280
## [30,] 18.3012752 19.4268490 17.2510380 14.097444913
## [31,] 12.3447054 11.6980019 19.0620243  4.303329764
## [32,]  5.7257070 15.2164725 11.2728937 16.278674426
## [33,] 14.7559481  7.4541879  6.5909483  6.155277486
## [34,] 16.6810862 15.3838782 19.9323444 13.754853713
## [35,]  6.2854156 10.7535437  4.6963935 18.653621580
## [36,]  9.8513310 18.2799090 12.2534393  2.315593297
## [37,] 13.9474753  3.7059288  2.1635706  2.554113758
## [38,] 12.8292471  5.6443683  9.7406514 13.564477148
## [39,] 12.8784583  1.8992483  1.9889165  8.578971918
## [40,] 19.5570681  4.2097416  3.2233153 16.688019559
## [41,]  8.2947067 19.5419799  5.6598574 19.428761336
## [42,]  2.3880956  5.9260435 11.6774467  1.409779554
## [43,] 10.5205932 14.5196605 14.6341532  9.195703864
## [44,]  4.5014670 15.7137567  3.3104182 14.031702369
## [45,]  9.7282353  2.1083549 17.3293553  1.738803359
## [46,]  7.4042960  4.7918926 14.1714827 19.858880322
## [47,] 19.6670036  5.4108974 15.2079907  5.061979881
## [48,]  7.7663823  2.0211699  2.9416822  0.990768713
## [49,]  4.5848968  2.3582768  7.1611393 13.726498936
## [50,] 12.4659509 19.8247311 13.4666496 15.738547053
m<-apply(y,2,mean)
m
##  [1] 10.401819  9.540540 10.307797 10.261198 10.253117  9.188950  9.849096
##  [8]  9.838603  9.813296  9.602321
s<-apply(y,2,sd)
s
##  [1] 5.885765 5.533551 5.880352 4.652955 5.462771 6.292274 5.749865 6.060184
##  [9] 5.583015 6.017083
 x<-0:20                # generate an integer sequence from 0 to 20
p<-dbinom(x,size=20,prob=1/4)   # p is a prob vector, p=Pr(X=x)
p
##  [1] 3.171212e-03 2.114141e-02 6.694781e-02 1.338956e-01 1.896855e-01
##  [6] 2.023312e-01 1.686093e-01 1.124062e-01 6.088669e-02 2.706075e-02
## [11] 9.922275e-03 3.006750e-03 7.516875e-04 1.541923e-04 2.569872e-05
## [16] 3.426496e-06 3.569266e-07 2.799425e-08 1.555236e-09 5.456968e-11
## [21] 9.094947e-13