#### caramel

##### Member

a) 200

b) 400

c) 800

d) 1600

**Could some one please explain. I could not understand the solution as given below**

the solution

a four fold increase in precision will approximately require FOUR FOLD^2 increase in replications . As a function of replications , the standard error is a function of SQRT(1/t). In order to educe the the standard errors from 0.4 to 0.1 , the replications need to increase from 100 to 1600

How was standard error 0.1 derived? Could someone detail the steps thanks