THE CORRELATIONS OF AREAS OF MATURED CROP AND THE RAINFALL. 379 



§ 8. Tables for finding the value of ' E c ' and of the probable error of ' r' for 

 the case of 20 observations. 



In dealing with agricultural statistics in the Panjab we shall frequently find that 

 a reliable series is only available for 20 years, or, that they fall into groups of 20. 

 It is desirable to tabulate some of the probable errors which are wanted approx- 

 imately. 



Table showing the values of log ^/j _ r *~ and log ( , ^/j _ r * \ for values of c r' ranging 



from *2o to '81. 



r 



log \/i—r* 



log E c ' 



A- 



93 



r 



log \/i— ■/>■ 



log E c ' 



j 

 ; A t 



r 



log y/ 1 — »-2 



log E c ' 



1 



•20 



T.99114 



1-16960 



•41 



1*96004 



1-13850 



218 



•62 



1-89465 



\ 

 1-07311 



445 



21 



•99021 



•16867 



98 



•42 



•95786 



•13632 



225 



•63 



•89020 



•06866 



463 



•22 



•98923 



•16769 



103 



•43 



•9556l 



13407 



233 



•64 



•88557 



•06403 



480 



•23 



•98820 



•16666 



108 



H4 



•95328 



•I3I74 



241 



•65 



•88077 



•05923 



497 



•24 



•98712 



•16558 



113 



•45 . 



•95087 



■12933 



250 



•66 



•87580 



•05436 



519 



•25 



•98599 



•16445 



119 



•46 



•94837 



•12683 



257 



•67 



•87061 



•04907 



538 



•26 



•98480 



•16326 



124 



H7 



•94580 



•12426 



267 



•68 



•86523 



•04369 



56i 



•27 



•98356 



•T6202 



129 



•48 



•94313 



•12159 



275 



•69 



•85962 



•03808 



584 



•28 



•98227 



•16073 



134 



•49 



•94038 



•I 1884 



285 



70 



•85378 



■03224 



608 



•29 



•98093 



•15939 



141 



•50 



•93753 



•H599 



295 



71 



•84770 



•02616 



636 



•30 



•97052 



•15798 



146 



•51 



•93458 



•II304 



304 



72 



•84134 



•OI980 



663 



•31 



97806 



•15652 



152 



•52 



•93154 



•11000 



314 



73 



•83471 



•OI317 



695 



•32 



•97D54 



•15500 



158 



•53 



•92840 



•10686 



226 



74 



•82776 



•00622 



727 



33 



•97496 



•15342 



163 



*54 



•92514 



•10360 



337 



75 



•82049 



2-99895 



763 



•34 



"97333 



-I 5i79 



171 



•55 



•92177 



•10023 



348 



76 



•81286 



2-99132 



801 



•35 



•97162 



•15008 



176 



•56 



•91829 



•09675 



361 



•77 



•80485 



2-98331 



843 



•36 



•96986 



•14832 



183 



•57 



•91468 



•09314 



372 



78 



79642 



2-97488 



888 



37 



•96803 



•14649 



190 



•58 



•91096 



•08942 



387 



•79 



78754 



2*96600 



939 



38 



•96613 



•14459 



196 



•59 



•90709 



•08555 



400 



•80 



77815 



2-95661 



994 



'39 



•96417 



•14263 



203 



•60 



•90309 



•08155 



4i5 



•81 



76821 



2-94667 





•40 



•96214 



•14060 



210 



•6l 



•89894 



•07740 



429 











