The sample data you collect has a mean of 20 and the standard deviation is 6. Assume that n=36. You calculate a 99% confidence interval. Next you calculate a 90% confidence for data with the same mean...

The sample data you collect has a mean of 20 and the standard deviation is 6. Assume that n=36. You calculate a 99% confidence interval. Next you calculate a 90% confidence for data with the same mean and standard deviation but now n=4.

Compared to the large sample confidence interval, the small sample condidence interval is:

1.  Much larger mainly because you use different t or z values.

2. Smaller because 90% of CI has a smaller range

3. Much larger mainly because the standard error is much higger with the smaller sample