Write the function of MS Excel

 Microsoft Excel offers a wide range of functions that serve various purposes, from basic arithmetic to complex statistical analysis. Here are some of the commonly used Excel functions along with their purposes:

1. **SUM**: Adds up a range of numbers.

   ```excel

   =SUM(A1:A10)

   ```

2. **AVERAGE**: Calculates the average of a group of numbers.

   ```excel

   =AVERAGE(B1:B10)

   ```

3. **IF**: Performs a logical test and returns one value for a TRUE result and another for a FALSE result.

   ```excel

   =IF(C1>100, "Above 100", "100 or below")

   ```

4. **VLOOKUP**: Looks for a value in the first column of a table and returns a value in the same row from a specified column.

   ```excel

   =VLOOKUP(D2, A2:B10, 2, FALSE)

   ```

5. **HLOOKUP**: Looks for a value in the top row of a table and returns a value in the same column from a specified row.

   ```excel

   =HLOOKUP(D2, A1:J2, 2, FALSE)

   ```

6. **INDEX**: Returns the value of a cell at the intersection of a specified row and column in a range.

   ```excel

   =INDEX(A1:C10, 5, 2)

   ```

7. **MATCH**: Searches for a value in a range and returns the relative position of that item.

   ```excel

   =MATCH("Apples", A1:A10, 0)

   ```

8. **COUNTIF**: Counts the number of cells that meet a criterion.

   ```excel

   =COUNTIF(A1:A10, ">50")

   ```

9. **SUMIF**: Adds the cells that meet a criterion.

   ```excel

   =SUMIF(A1:A10, ">50")

   ```

10. **CONCATENATE**: Joins several text strings into one string (Note: In newer versions of Excel, `CONCATENATE` is replaced by `CONCAT` or `TEXTJOIN`).

    ```excel

    =CONCATENATE(A1, " ", B1)

    ```

11. **TEXT**: Formats a number and converts it to text.

    ```excel

    =TEXT(A1, "0.00")

    ```

12. **LEFT, MID, RIGHT**: Extracts a specified number of characters from a text string.

    ```excel

    =LEFT(A1, 3)  // First 3 characters

    =MID(A1, 2, 3)  // 3 characters starting from the 2nd character

    =RIGHT(A1, 4)  // Last 4 characters

    ```

13. **NOW**: Returns the current date and time.

    ```excel

    =NOW()

    ```

14. **TODAY**: Returns the current date.

    ```excel

    =TODAY()

    ```

These functions can be combined in various ways to perform more complex calculations and data analysis. Excel's flexibility and extensive function library make it a powerful tool for data management and analysis.