Definition Placenta previa: Abnormal location- of the placenta over,orin close proximity to the internal os. Incidence: approximately 1 /250 pregnancy nulliparas: 1/1000~1/1500 pregnancy grandmultiparas: 1/20
The stock Price Assumption Consider a stock whose price is s In a short period of time of length At the change in then stock price S is assumed to be normal with mean Sdt and standard deviation os√△, that is, S follows geometric Brownian motion ds=u Sdt+oSdz Then dInS=( )dt+oda