In describing confidence intervals on a mean z and t interva

In describing confidence intervals on a mean, z and t intervals are frequently mentioned. How are z and t confidence intervals different? Choose one interval and give an example of how it could be applied within an operations or production environment that is different from those mentioned in the overview.

Solution

Z distribution is a special type of normal distribution with 0mean and 1 variance. It is bell shaped. On the otherhand, t-distribution can be think of as a cousin of standard normal distribution. It has 0 mean, it is bell shaped bt shorten and flatter. t-distribution is mainly used to estimate population mean of normal distribution. It is applied for small population and unknown variance; degrees of freedom=n-1.