Indeed, for some gems, such as diamonds, the price per carat can increase exponentially as the gem size increases. Therefore, a 1 carat stone may cost $1,000 while a 2 carat stone may cost $4,000. This means that good quality sapphires and rubies in larger sizes tend to have a much higher price per carat.
Re: Convert positive # to negative. Hi, if you positive number is in A1, use the following formula to convert it to a negative number =A1*-1 Time values can not be negative. Microsoft MVP http://www.teylyn.com Twitter: http://twitter.com/IngeborgNZ. Microsoft MVP.
Note: To get the first negative number of the list, you just need this formula: =INDEX(A2:A18,MATCH(TRUE,A2:A18<0,0)), and remember to press Ctrl + Shift + Enter keys simultaneously. If you need to find the last positive or negative number in a list of values, you can also apply array formula. Note: To get the last negative number of the list, you just need this formula: =LOOKUP(9.99999999999999E+307, IF($A$2:$A$18 < 0, $A$2:$A$18)), and remember to press Ctrl + Shift + Enter keys together.