22 ON PROBABILITY.
greater than ¢.(b — 1) times the parcel immediately preceding it, and very
much greater than i times the sum of all the parcels which precede it.
Exactly the same reasoning will show that if p,,, can be made greater than
i.(a — 1) times p,,, _ ,y that is, iin > i.(a—1) the parcel of the second
limit, will, with the same value of am, be more than i times greater than all
the parcels which follow it.
35. Let a be that one of the quantities « and 5, which is not the least,
A value of m, which will make p™“ greater than i. (¢ — 1) times p,,,_.., and
than .(@— 1) times Pp orm Will evidently satisfy both the above-mentioned
conditions.
Pua. (ma+1).. (ma m) GC) = (mab +b)..(mab-4 mb)
Pmagm (mb—{m—11%1)..mb\a (mab— {m-1}%}a).. mab
b
The last pair of factors here is meh mh or el and any other
3 mab a
pair, such as the #*, is é
mab-rb sx so @1
br TD
if mab4+rb>@-+1)(@mb—m 47),
that is, if b< a+ 1,
which by supposition itis. Therefore
na a + 1 nm
iY
Pmatm a
for there are m factors in this continued product.
Pos _ (mb+1)..(mb +m) NE paid auncidn }
Pna-m (Mma—{m—1%})..ma\b (mab—.{m—1%}b)...mb
Any factor, as the +, here
: _ mab+ra wa a+ 1
aU AT which is > £2 en
if admdb+t+n>=@+1).b(ma—{m-r}),
that is, if ra(@—0b)+ (m—1r).0>=0,
which it must always be, for neither @ — 4, nor m — #, can ever become
negative,
{ Pua a - by 3 i: + 1 m ;
oo — —or oe Pie AS —) = 3%
log. ¢ (a —
or mit one 1
log.(@ + 1) — log. a
and with this value of m both the necessary conditions are satisfied.
36. Therefore the probability
_ 1st parcel + 2d parcel + a,
1st parcel + 2d parcel + a,, + sum of other parcels’
or since lst parcel +4 2d parcel > 4. (sum of other parcels)
= ¢ (sum of other parcels) -} %,