Case 1: Century National Bank
The Century National Bank has offices in several cities in the Midwest and the southeastern part of the United States. Mr. Dan Selig, president and CEO, would like to know the characteristics of his checking account customers. What is the balance of a typical customer? How many other bank services do the checking account customers use? Do the customers use the ATM service and, if so, how often? What about debt cards? Who uses them, and how are they used?
To better understanding the customers, Mr. Selig asked Mrs. Wendy Lamberg, Director of planning, to select a sample of customers and prepare a report. To begin, she has appointed a team of us. Then, we started by selecting a random sample of 60 customers. In …show more content…

If one or more of these values are either extremely large or extremely small, the mean might not be an appropriate average to represent data 2. The mean is also inappropriate if there in an open-ended class for data tallied into a frequency distribution.
Sample mean is also known as statistic.
It has been pointed out that for data containing one or two very large or very small values, the arithmetic mean may not be representative. The central point for such data can be better described using a measure of central tendency called the median.
Median is the midpoint of the values after they have been ordered from the smallest to the largest, or the largest to the smallest.
Major properties of median are: 1. Median is unique, like the mean, there is only one median for a set of data. 2. It is not affected by extremely large or small values 3. It can be computed for a frequency distribution with an open-ended class if the median does not lie in an open-ended class 4. It can be computed for ratio, interval and ordinal levels data.
Sample Mean Estimation:

89992 / 60 = 1499.87 Median Estimation: (No 30 + No 31) / 2 (1593 + 1616) / 2 = 1605 Based on sample mean estimation we can say that single value 1499.87 represent all 60 different checking accounts, but when we estimated median we realized that this single value has been