Consider the following AR(1) model: yt=yt1+et where et is WN(0,1). Derive the Yule-Walker equation and calculate the estimate of given the following sample values: y1=4,y2=1,y3=3 and y4=8. Note that T=4. Be sure to show all your workings. Consider the following AR(1) model: yt=yt1+et where et is WN(0,1). Derive the Yule-Walker equation and calculate the estimate of given the following sample values: y1=4,y2=1,y3=3 and y4=8. Note that T=4. Be sure to show all your workings