What is confidence interval. All that apply.

Please, help me.

What is confidence interval. All that apply.

1- Decreasing the confidence level increases the width of a confidence interval

2- Increasing sample size decreases the width of a confidence interval.

3- Decreasing sample size decreases the width of a confidence interval.

4- A confidence interval with a 100% confidence level can be computed.

5- Increasing the confidence level increases the width of a confidence interval.