If Anyone can Help on Quest. 12 Monte carlo on Asset Allocat 2012, understand, understood, objective

RMontgomery

Could not understand the explanation of above mentioned Quest.
My question is on Exhibit 8 box representing line probability 90%, 75%, 50%, 25% & 10%. so looking at the Monte Carlo Probability line $2067044 which is 90% prob line, objective can be achieved of $630000 at age 75 in 2012. why answer is ‘can not avhieve’.
If there is any one who understood………..