The function wizard is a built-in Excel feature. To invoke it,
click the 
icon in
the standard toolbar just below the menu bar. The function wizard lists
function categories and function names. If you choose the Queueing ToolPak
function category you will see a list of all the functions provided by the
Queueing ToolPak. Clicking the name of a function will show its syntax and
a brief description of what it calculates.
The formula palette is another built-in Excel feature that is
useful when you remember the name of a function but not its arguments.
Enter the equals sign followed by the name of the function in an empty
cell. Then click the 
icon just above the column headings of the spreadsheet. If you typed the
name of the function correctly, you will see a dialog box listing the arguments for the
function. Enter the arguments and click "OK."