## Excel Function → FREQUENCY

We learn about a statistical function called 'FREQUENCY' which is an array function. Unlike a normal function, an array function returns a group of values in a range of cells. After entering the formula using an array function, one cannot simply press ENTER to return values. In Excel for Windows, one must press the key combination of CTRL-SHIFT-ENTER for the array function to execute. In Excel for MacOS, the key combination is CMD+RETURN.

Let's learn how to use it with an example. The image below displays the marks earned by a group of students in an exam. The maximum score on the exam is 100. We assign a grade to every student based on his or her score. Every grade has a defined range of scores. For example, a student must score between 90 and 100 to earn the 'A' grade. We wish to know the number of students in each grade which can be achieved by using the function 'FREQUENCY'

Using the function 'FREQUENCY' in Excel

This function takes two inputs ( or arguments). One is the data range (scores of students) and the other is the bin range (the maximum value in every interval associated with a grade). We see in this example that 3 students have a 'B' and 3 a 'D'.

## Excel Function → NETWORKDAYS()

This function counts the number of business days between two dates. It requires two parameters: a start date and an end date. In addition, you can supply a third parameter to specify holidays that Excel should disregard.

Suppose that your supervisor asks you to submit your work by a certain date. You start work today. You would like to know how many days you would actually work without considering the weekend and holidays. We demonstrate the value of this function through the example below.

The number of business days between the two dates is 128 ignoring the weekends and the holidays

Prof. Anand S