estimation of sample size with proportions

例句：

1. 1. The team estimates that the project will take six months to complete.
   团队估计这个项目需要六个月的时间来完成。
2. 2.The surveyor estimated the cost of the house at $300,000.
   测量师估计这所房子的造价为30万美元。
3. 3. He estimated his expenses for the trip to be around $500.
   他估计这次旅行的费用约为500美元。