The value of a standard commercial lot in Zone A has a population mean of $120,000 and a population standard deviation of $25,000,
but lot values are not normally distributed.
If we select one, random lot from Zone A, a 95% confidence interval
says that our random lot will have a value between:
(You might use any of the following facts if appropriate...)
For any normally distributed random variable:
.
90% of the values lie within 1.645 standard deviations of the mean
95% of the values lie within 1.960 standard deviations of the mean
. 99% of the values lie within 2.576 standard deviations of the mean