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# Excel/Expert Profile

## Bob Umlas

U.S.
Available
##### Expertise

I`m a Microsoft Excel MVP (Most Valuable Professional) and have been since the inception of the program in 1995. I can answer every kind of Excel question except: API, Importing/exporting to other programs (powerpoint, word,...) Also check out my in-person training link at http://www.thumbtack.com/ny/new-york/excel-training/

##### Experience in the area

Worked with MS Excel since version 0.99 (on the Mac!). Was contributing editor to Excellence Magazine, having written >300 articles. John Walkenbach said of me "I finally met someone who knows as much about Excel as I do."

##### Publications

Excellence, The Expert, Microsoft

##### Education/Credentials

BA in math, Hofstra University, 1965

##### Awards and Honors

MVP
Led sessions for the Convergence 2004-2006 seminar on Excel tips & tricks

##### What do you still hope to achieve/learn in this field?

XML

See my book, This isn't Excel, it's Magic! at http://www.iil.com/iil/excelmagic

This expert accepts donations:

### Recent Reviews from Users

K = Knowledgeability    C = Clarity of Response    P = Politeness
Philippe10/19/16101010
ABDUL RAHMAN10/06/16101010DEAR MR. BOB NOW THE SOLUTION IS .....
ABDUL RAHMAN09/29/16101010THANK YOU VERY,VERY MUCH THE FORMULA .....
Joe09/28/16101010
Malcolm09/17/16101010Thanks Bob

### Recent Answers from Bob Umlas

#### 2016-10-15 polynomials of degree higher than 3:

For an 8th-degree polynomial, you will have 9 coefficients.  So for example, select E5, then enter this:  =INDEX(LINEST(\$B\$5:\$B\$35,\$A\$5:\$A\$35^COLUMN(\$A:\$H),,TRUE),,COLUMN(A1))  then fill right to M5. These

#### 2016-10-11 Date/age calculations with pre-1900 dates:

This will give the answer in Years (or fraction of years, like 1.5):  Enter from date in a cell, say A1, and end date in A2, enter =Age(A1,A2)    Function Age(From, Too) As Double      Dim n As Long, From2

#### 2016-10-10 Date/age calculations with pre-1900 dates:

Dates before 1900 are only available through VBA. You'll notice that simply entering a date before 1900 is left-aligned, hence it's treated as text.

#### 2016-09-29 BUILDING CORRECT EXCEL FORMULA:

Let's say on sheet2 the dates are in row 2 and the first product (550) is in cell A5. Enter this formula in cell B5, but before pressing enter, hold the ctrl+shift keys down:  =INDEX(Sheet1!\$F:\$F,MATCH(\$A5&B\$2

#### 2016-09-21 Excel simple sums:

Most likely cause is that the data you're summing is text. If your formula is =SUM(A1:A10), for example, try =SUM(A1:A10*1) but entered via ctrl+shift+enter (note the "*1" inside the formula). If that