Question

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.

Answer 1

The Z and T Confidence intervals differs as follows:

Z-Confidence interval:

1.The confidence interval for the difference between population means when the standard deviations of two samples are known
2.The confidence interval for an unknown population mean when standard deviation is known
3.uses the number of data items to calculate the confidence interval for an unknown proportion of successes
4.uses the number of data items to calculate the confidence interval for the difference between the proportion of successes in two populations

T-Confidence interval:​​​​​​​

1.The confidence interval for the difference between two population means when both population standard deviations are known
2.The confidence interval for an unknown population mean when the population standard deviation is unknown
3.T distribution shares characteristics of normal distribution, such as: bell-shape, symmetric about the mean, mean median or mode are equal to 0 and located in center of distribution

Example:

Example of using the T interval could be used in airport daily operations to calculate the coefficient of interval between arrival and departure times (turnaround) of air crafts. The reason is to find out how many times one specific gate could be used for the air crafts daily.