Sample Random Nos Table

What are random numbers? They are the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 scrambled in a particular fashion. Table 5~1 is an example of a table of random numbers. The various digits are arranged in such a way that all digits appear with approximately the same frequency in the table. Furthermore any given digit has no relationship to the digit above, below, to the right, or to the left of it. In other words, the various digits are scattered at random. However, for convenience, 40 digits, in groups of five, are placed on each line. A practical sampling problem will best illustrate the use of the table of random numbers in selecting a simple random sample. Let us assume that we wish to select 10 accounts reccivable from a ledger containing 6532 accounts. As a first step, we must assign a serial number to each account in the ledger-in our case, a four-digit serial number. (If the number of accounts in the ledger had been 623, we would have assigned a three-digit serial number to each account. Thus the number of digits of which a serial number consists depends on the total number of accounts in the ledger.) We now assign 0001 to the first account, 0002 to the second account, 0123 to the 123rd account, and 6532 to the last account. Once all accounts in the ledger are serialized, we can begin to select our sample by reading the first four digits from the first line of the table of random digits. The number is 7899. Since no account in the ledger corresponds to this number, we move down and read the first four digits of the second line. The number 0490 corresponds to the 490th account in the ledger, which becomes our first account in the sample. Continuing in the same fashion, we obtain the other nine accounts: 4658, 2924, 1715, 5071, 3944, 0102, 0833, 3970, 2590. (Note that when a serial number appears twice, it must be ignored on the second appearance.) The table of random numbers could have been used in some other manner. We could have read our first four digits from any place in the table. Furthermore, in selecting our second four digits, we could have moved sideways or crosswise, so long as our movement remained systematic. An illustrative page of random numbers Line (1) (2) (3) (4) (5) (6) (7) (8) 78994 36244 02673 25475 84953 61793 50243 63423 2 04909 58485 70686 93930 34880 73059 06823 80257 3 46582 73570 33004 51795 86477 46736 60460 70345 4 29242 89792 88634 60285 07190 07795 27011 85941 5 68104 81339 97090 20601 78940 20228 22803 96070 6 17156 02182 82504 19880 93747 80910 78260 25136 7 50711 94789 07171 02103 99057 98775 37997 18325 Table 5-1 (Continued) Line (1) (2) (3) (4) (5) (6) (7) (8) 16 71345 03422 01015 68025 19703 77313 04555 83425 17 61454 92263 14647 08473 34124 10740 40839 05620 18 80376 08909 30470 40200 46558 61742 11643 92121 19 45144 54373 05505 90074 24783 86299 20900 15144 20 12191 88527 58852 51175 11534 87218 04876 85584 21 62936 59120 73957 35969 21598 47287 39394 08778 22 31588 96798 43668 12611 01714 77266 55079 24690 23 20787 96048 84726 17512 39450 43618 30629 24356 24 45603 00745 84635 43079 52724 14262 05750 89373 25 31606 64782 34027 56734 09365 20008 93559 78384 26 10452 33074 76718 99556 16026 00013 78411 95107 27 37016 64633 67301 50949 91298 74968 73631 57397 28 66725 97865 25409 37498 00816 99262 14471 10232 29 07380 74438 82120 17890 40963 55757 13492 68294 30 71621 57688 58256 47702 74724 89419 08025 68519 31 03466 13263 23917 20417 11315 52805 33073 07723 32 12692 32931 97387 34822 53775 91674 76549 37635 33 52192 30941 44998 17833 94563 23062 95725 38463 34 56691 72529 66063 73570 86860 68125 40436 31303 35 74952 43041 58869 15677 78598 43520 97521 83248 36 18752 43693 32867 53017 22661 39610 03796 02622 37 61691 04944 43111 28325 82319 65589 66048 98498 38 49197 19436 63948 38947 60207 70667 39843 60607 15328 39 87291 71684 74850 76501 93456 95714 92518 40 39143 64893 14606 13543 09621 68301 69817 52140 41 82244 67549 76491 09761 74494 91307 64222 66592 42 55847 56155 42878 23708 97999 40131 52360 90390 43 94095 11751 95970 07826 25991 37584 56966 68623 83454 44 69469 25521 44097 07511 88976 30122 67542 45 69902 08995 27821 11758 64989 61902 32121 28165 46 21850 23332 23336 92101 25392 43294 10493 37819 47 75850 46992 25165 55906 62339 58958 91717 15756 48 29648 22086 42581 85677 20251 39641 65786 80689 49 82740 28443 42734 25518 82827 35825 90288 32911 50 36842 42092 52075 83926 42875 71500 69216 01350