## What does a wide confidence interval suggest?

Wider confidence intervals in relation to the estimate itself indicate instability. For example, if 5 percent of voters are undecided, but the margin of error of your survey is plus or minus 3.5 percent, then the estimate is relatively unstable.

**Is it better to have a wide or narrow confidence interval?**

Apparently a narrow confidence interval implies that there is a smaller chance of obtaining an observation within that interval, therefore, our accuracy is higher. Also a 95% confidence interval is narrower than a 99% confidence interval which is wider. The 99% confidence interval is more accurate than the 95%.

### Why does the confidence interval get wider as the confidence level increases?

Increasing the confidence will increase the margin of error resulting in a wider interval. Increasing the confidence will decrease the margin of error resulting in a narrower interval.

**What does a narrow confidence interval mean?**

A large confidence interval suggests that the sample does not provide a precise representation of the population mean, whereas a narrow confidence interval demonstrates a greater degree of precision.

#### Why do confidence intervals get wider at the ends?

As you draw larger and larger random samples from the same population, the confidence intervals tend to become narrower. As you increase the confidence level for a given same sample, say from 95% to 99%, the range becomes wider.

**Is a higher confidence level wider?**

The greater the confidence level, the wider the confidence interval. If we assume the confidence level is fixed, the only way to obtain more precise population estimates is to minimize sampling error.

## Why do higher confidence levels have wider intervals?

It’s impossible to say without seeing the sample data. Increasing the confidence will increase the margin of error resulting in a wider interval. Increasing the confidence will decrease the margin of error resulting in a narrower interval.

**Why does a confidence interval get wider the more confident you become?**

So it is with confidence intervals. The more confident we want to be, the wider the interval must be. This is true because of the formula for the margin of error, E = zc*σ/sqrt(n). Assuming the standard deviation σ and sample size n stay constant, E increases as the critical value of z increases.