Assuming that the population is normally distributed, construct a $90\%$ confidence interval for the population mean, based on the following sample size of $n=6.$

$1,2,3,4,5,$ and $21.$

In the given data, replace the value $21$ with $6$ and recalculate the confidence interval. Using these results, describe the effect of an outlier $($that is$,$ an extreme value$)$ on the confidence interval, in general.

Find a $90\%$ confidence interval for the population mean, using the formula or technology.

$,($Round to two decimal places as needed.$)$