Richard, I have sent you a specimen Excel file with your objective satisfied. If anyone else would like a copy, email me OFF LIST and it's yours. Duncan Williamson _____ From: Economics, business, and related subjects [mailto:[log in to unmask]] On Behalf Of Richard Young Sent: 09 October 2004 10:16 To: [log in to unmask] Subject: Plotting marginal values in Excel Thanks to the list I can now plot demand & supply curves in Excel - not bad of a Head of ICT :-) Ah, but what to do about marginal values eg marginal product and marginal cost With pen and paper you plot half way between what is and what was eg plot the marginal product of the 5th worker half way between 4 and 5 on the x axis where labour is plotted I attach a spreadsheet where I have managed to plot AP & MP but MP does not intersect AP at its highest point because Excel is plotting marginal product at 5 - not 4.5 HELP PLEASE - can you get Excel to plot marginal values half way? You may ask why am I bothering - at AS level 1. I do like my students to use ICT and nothing like a context 2. I have an able class 3. I find just drawing curves eg a set short run average cost curves to illustrate economies of scale builds awareness but not understanding. Why is the MC curve shaped like an umbrella? Actually getting into the nitty gritty of diminishing returns gives students the necessary background to understand the short run, diminishing returns for a constant outlay on wages. Never expect to answer a question on deriving curves. But at least they can get their heads round why so why cost curves are the shape they are. Getting student to work through worked examples is one approach. I am sure there are others. Regards Richard Young 31 Newland Mill Witney OX28 3HH 01993 200110 Preferred private email address: [log in to unmask]