关于土耳其电子签证e-visa的adequate financial means

土耳其电子签证最后提到
The applicant must hold travel documents in accordance with his travel purposes. (Return ticket, hotel reservation, adequate financial means) (When we say “adequate financial means”, we do not require a specific amount of money. We mean that the applicant must have financial means that are sufficient to sustain all his needs while in Turkey.)


请问什么样的材料算是符合要求的？如果几个朋友同行，每个人都要准备相关的写有自己名字的英文财产证明吗，只准备一个人的行不行？