A 99 percent confidence interval would be wider than a 95 percent confidence interval (for example, plus or minus 4.5 percent instead of 3.5 percent). A 90 percent confidence interval would be narrower (plus or minus 2.5 percent, for example).

Is a 90% or 95% confidence interval wider?

Precision - Role of Confidence Level

The confidence level is typically set in the range of 99% to 80%. The 95% confidence interval will be wider than the 90% interval, which in turn will be wider than the 80% interval.

Is 95% or 99% confidence interval wider?

For example, a 99% confidence interval will be wider than a 95% confidence interval because to be more confident that the true population value falls within the interval we will need to allow more potential values within the interval. The confidence level most commonly adopted is 95%.