1. A 95% confidence interval estimate for proportion of Americans who think Abraham Lincoln is United States' most outstanding President is 65% to 75%. If the more precise estimate is requested, then confidence level
- Increases
- Remains the same
- Decreases
- None of the above
2. The width of the confidence interval estimate of mean (µ, like average credit card debt for American college students) narrows when the
- Level of confidence raises
- Sample size raises
- Sample size reduces
- All of the above