Data junkies, rejoice: there's a fun new tool called Guesstimate for calculating uncertain values. Or in founder Ozzie Gooen's words, "a spreadsheet for things that aren't certain." Rather than a thick stack of Excel tabs with Solver, Guesstimate offers a simplified Monte Carlo simulation in your browser.
I ran through a quick example that nerd parents will appreciate: How long does it take to get your child ready for preschool? In my case, about 120 minutes based upon 17 metrics. Spookily accurate.
Feel free to enter your own value ranges in my test simulation, or browse other public models here. Enjoy...school is back on Monday!
(hat tip to Lane)