00:01
So for this problem, we are asked which of the options will decrease the margin of error for a confidence interval.
00:12
So the margin of error for a confidence interval, for population mean, for instance, is typically going to be given by, normally it's a z score, critical z value, multiplied by our, if we're doing this as a z based interval.
00:27
We multiply by the standard deviation, we divide by the square root of the sample size.
00:32
And of course we just use t and s if we're doing something which requires a t distribution.
00:38
So we can see that the margin of error is proportional to 1 over the square root of the sample size.
00:51
So it is scaling inversely with the sample size.
00:55
So that means that as n, the sample size increases, the margin of error will decrease...