Authorities there must buy new equipment." The U.N.agency reports mortality rates in Gaza are about 30 percent higher than among the Palestinian population in the West Bank.

VOA: standard.2010.06.01

They divide by n-1 to make it an unbiased estimator of the population variance, but I'm just going to show it in a simple way here.

当除以n-1表示的是对总体的,无偏估计,我在这里只是说的简单一点

耶鲁公开课 - 金融市场课程节选

Yahya Kane is a program specialist with the U.N.Fund for Population Activity.

VOA: standard.2009.12.23

The U.N.Fund for Population Activity and the World Health Organization are working with national ministries of health in a global campaign to end fistula that now covers more than 40 countries in Sub-Saharan Africa, Asia,and the Middle East.

VOA: standard.2009.12.23

"These targets are set for 2015 and are to achieve at least 90 percent measles vaccination coverage nationally and 80 percent coverage in every district, reduce measles cases to less than five per million population, reduce measles mortality by U.N.health agencies have made huge strides in reducing the number of children dying from measles.

VOA: standard.2010.05.21