Missing Data Calculator App

This calculator app is designed on the basis of calculating the average of all the examples (each patient) divided by the total number of examples.
The android interface is simple consisting of a text box for user to enter the specified values of a parameter or variable and each value should be separated by a comma. The values not separated by comma will not be calculated.
The user is able to enter infinite number of values in the provided text box.
The calculator app performs addition of all the examples divided by total number of examples to calculate the mean.
The average (missing data) is found in the text view box on clicking for the missing value button. Now the researcher is able to substitute the mean shown in the box, thus replacing the missing data.