Using What-If Analysis, you can visualize the effects of different variables, making it easier to assess risks and opportunities. In Excel, three primary tools are available for performing What-If ...

The temperature on a summer day may be in the 80s or 90s. So why does it feel so much hotter? That's the heat index. Here's how it works.

See how to use data.table's special .SD symbol to perform calculations and other tasks by group ...