Explanation
The value in G5 is hard-coded. The formula picks up the value in G5, then subtracts the value (if any) in E6 and adds the value (if any) in F6. When the credit or debit values are empty, they behave like zero and have no effect on the result.
When this formula is copied down column G, it will continue to calculate a running balance in each row.
Dealing with blank values
To display nothing in the balance column when the credit and debit columns are empty, you can use the IF function with AND and ISBLANK like this:
=IF(AND(ISBLANK(E6),ISBLANK(F6)),"",G5-E6+F6)
This formula will return an empty string ("") when both credit and debit cells are empty, and returns the running balance if either number exists.
Note: this only handles bank credit and debit values at the end of the table, not rows in between.
Explanation
The coefficient of variation measures the relative variability of data with respect to the mean. It represents a ratio of the standard deviation to the mean and can be a useful way to compare data series when means are different. It is sometimes called relative standard deviation (RSD).
In this contrived example, the standard deviation is calculated in column H with the STDEV.P function:
=STDEV.P(B5:F5)
Notice that the standard deviation is the same for all data series (1.414214) even though the means vary substantially. To calculate the coefficient of variation (CV), the formula in I5 is:
=H5/AVERAGE(B5:F5)
This formula divides the standard deviation in H5 by the mean of B5:F5, calculated with the AVERAGE function. The result is a decimal value, formatted with the percentage number format. The calculated CV values show variability with respect to the mean more clearly. In the first data series, the CV is nearly 50%. In the last data series, the CV is only .12%.
