Question

For a given confidence level, you can get a smaller margin of error by selecting a bigger sample?

Answer 1

Solution:

Margin of error for z interval is given by:

and in case t interval,

We can see Margin of error E is inversely proportional to sample size n, thus for fixed confidence interval and standard deviation, if sample size n increases, then margin of error decreases.

Thus For a given confidence level, you can get a smaller margin of error by selecting a bigger sample is correct or True statement.