Causes of the methodology：There needs to be a greater chance that the estimate would be more accurate than a point estimate.
The definition of interval estimates：An estimate that specifies an interval and the probability of the overall unknown parameter covered by this interval【The corresponding probability is called confidence level 1-α】。
The relationship between confidence level and confidence intervals： The higher the confidence level is, the wider the confidence interval will be. The higher the confidence level, the wider the confidence interval.
The general formula for confidence intervals：point estimate ± (critical value)(standard error)