Module Title Business Forecasting标题商务预报
论文题目:business forcasting
Question_2 问题
i) a linear trend; and 线性趋势 Hence discuss the level of differencing required to make such trends stationary.因此,商谈水平使这种趋势静止所需的差分。 (10 marks) b) Explain what is meant by the following ideas in time series modelling.英国coursework指导解释指的是什么时间序列建模以下思路。 i) auto-regressive component; ii) moving average component.自回归成分;2)移动平均分量。 The general Box-Jenkins ARIMA(p,d,q) model can be written as:一般箱詹金斯ARIMA(P,D,q)的模型可以写成: where d is the level\ of differencing; b(L) is a p-th order polynomial; and c(L) is a q-th order polynomial.其中d是差分的水平\;(L)是一个p-阶多项式。(L)是第q阶多项式。 iii) Explain what this notation means.解释这个符号是什么意思 Hence explain the structure of the following models for a time series yt.因此,解释以下车型的结构为一个时间序列YT iii) ARIMA(1,0,0) ; iv) ARIMA(0,1,1) , a0 = 0 v) ARIMA(1,2,1) (40 marks)
b) Sales of a painkilling drug for a UK based pharmaceutical company have been collected as in CW_Sales_1011, which is available as an Excel file.销售总部设在英国的制药公司的止痛药已经收集在CW_Sales_1011,这是作为一个Excel文件。 Total: 100 marks |