S19=[(a1+a19)×19]/2=19×a10
T19=[(b1+b19)×19]/2=19×b10
(S19)/(T19)=(19×a10)/(19×b10)=(a10)/(b10)
(S19)/(T19)=22/20=11/10
(a10)/(b10)=11/10
S19=[(a1+a19)×19]/2=19×a10
T19=[(b1+b19)×19]/2=19×b10
(S19)/(T19)=(19×a10)/(19×b10)=(a10)/(b10)
(S19)/(T19)=22/20=11/10
(a10)/(b10)=11/10