To know this, you oftentimes even need to know this parameter. For example, in the situation where the parameter that we're trying to estimate and construct confidence intervals for is say the population proportion, what percentage of the population supports a certain candidate? Well, in that world, the statistic is the sample proportion. So we would have the sample proportion, plus or minus z star, times, well, we can't calculate this unless we know the population proportion. So instead, we estimate this with the standard error of the statistic, which in this case is p hat times one minus p hat, the sample proportion times one minus the sample proportion over our sample size. If the parameter we're trying to estimate is the population mean, then our statistic is going to be the sample mean. So in that scenario, we are going to be looking at our statistic is our sample mean, plus or minus z star.