ETS样题16题
a student makes 10 one-second measurements of the disintergration of a sample of long -lived radioactive isotope and obtains the following values
3,0,2,1,2,4,0,1,2,5
how long should the students count to establish the rate to an uncertainty of 1 percent?
A 80s
B 160s
C 2000s
D 5000s
E 6400s