when are confidence intervals useful why is confidence interval useful confidence interval for parameter definition when is a confidence interval useful when to use confidence intervals when are confidence intervals useful what are confidence intervals useful confidence intervals statistics when are confidence intervals useful when to use confidence interval when are confidence interval useful? when are confidence intervals useful why is confidence interval useful when can i find confidence intervals why are confidence intervals useful confidence interval meaning when is a confidence interval useful when are confidence intervals useful when is confidence interval useful when are confidence intervals useful