If you use Excel to model businesses, business processes, or business transactions, this course will change your life. You’ll learn how to create tools for yourself that will amaze even you. Unrestricted use of this material is available in two ways.

As a stand-alone Web site
It resides on your computer, and you can use it anywhere. No need for Internet access.
At this Web site
If you have access to the Internet whenever you want to view this material, you can purchase on-line access. Unlimited usage. I’m constantly making improvements and you’ll get them as soon as they’re available.

To Order On Line

 Order "Spreadsheet Models for Managers, on-line edition, one month" by credit card, for USD 69.95 each, using our secure server, and receive download instructions by return email.
 Order "Spreadsheet Models for Managers, on-line edition, three months" by credit card, for USD 199.00 each, using our secure server, and receive download instructions by return email.

To Order by Mail

 Make your check payable to Chaco Canyon Consulting, for the amount indicated: For the download: USD 199.00 For access online for three months: USD 199.00 For access online for one month: USD 69.95 And send it to: Chaco Canyon Consulting 700 Huron Avenue, Suite 19C Cambridge, MA 02138

To use the course software you’ll need some other applications, which you very probably already have. By placing your order, you’re confirming that you have the software you need, as described on this site.

 Matrix multiplication examples

Here are four examples of matrix products. In each case, the left side of the equality contains the two matrices that are being multiplied, and the right side shows the result. The Excel worksheet function that produces the matrix product of two matrices is mmult.

Of the four examples shown here, only one is a legal product if the order of the two matrix factors on the left side of the equality is reversed. The one that’s legal in reverse order is the lower left product. Try reversing the order, and notice that the result of the reversed-order product isn’t equal to the result shown. This is an illustration of the fact that matrix multiplication isn’t commutative.

Sometimes we want to form the product of three or more matrices. Using mmult, we must do this by first forming the product of two of them, then multiplying the result of that by the third, and so on, maintaining the correct order, of course. It doesn’t matter how you pair them, as long as you preserve the order, because matrix multiplication is associative.

In your add-in for this course, you’ll find a function MMMult, which can handle up to ten matrix factors.