[ 317 ] 
21. Rht QJs greater than the arithmetical mean 
between D ht F and D h f C. This appears from the 
latter part of Art. 19. for what is there proved of the 
ordinates muft hold true of the contemporary areas 
generated by them. And though beyond the points 
at which the ratio of the decreafe of QX t0 the de- 
creafe of F t comes to an equality with the ratio of 
the decreafe of Q t_ to the decreafe of C f, the excefs 
of F t above Qj begins to grow larger than before in 
refped of the excefs of Qj above C /; yet as it ap- 
pears from the laft article, that above five fixths of 
the areas R Q^W h and A C F H are generated be- 
fore the ordinates come to thefe points, and as alfo 
beyond thefe points the faid ratios, ’till they become 
neither p nor q are very fmall, or even not lefs than 10, it will 
be nearly an equal chance, that the probability of the event lies 
p V P q , P p q 
between \- 
n 
and — 
y in 3, — an 2, n 
V !t 3 
It will be 
2 n 
p p q 
the odds of two to one that it lies between “ + ' 
fL \/ 91 
, p ^ f ? 
and - — "y^===~==— 
H. V n 3 — n 2 
n ■ v' n 3 — n z 
j and the odds of five to one that it lies 
p V X p q 
between - + , ■■ ~=-—, 
n v ?! 3 — » 1 
^ P_ zpq 
Tl V n 3 — n 1 
For in- 
flance ; when p = 1000, q = 100,* there will be nearly unequal 
i° 1 
chance, that the probability .of the event lies between — + yy- 
101 t 10 1 
and ; two to one that it lies between — + and 
11 ifc»3 11 J i5 
10 1 ... 10 1 . 
— — and five to one that it lies between — + 5— and 
11 115 II Ol 
10 
II 
I 
' 8 ? 
negative 
