ocd much??? i never thought you would have finished this one, but you’ve proved me wrong. kudos

I’ll have to agree with Beau…OCD displayed in its finest fashion.  But, I’m glad someone out there had the patience to complete such a project, I know I would never have made it.  All the blue ones would be eaten, and the co-workers would have received half-full bags of brown M&M’s.

Is orange and blue dye less expensive than the others?

There are some obvious errors in the statistical analysis presented.
* Either variance or standard deviation are calculated wrongly, since if s is the standard deviation s^2 is the variance.
* The variance and standard deviation make no sense if given in absolute numbers (of M&Ms), since the packs are not all of the same size. Rather, they should be given as percent points.
* Obviously, the t test, p value and confidence intervals are missing to test the validity of your conclusions.

I did the same analysis way back in the 1980s when I was working at DEC. Very similar results. Used to really look forward to the packs with outliers, like 18 Greens. Gained 10 pounds during the testing, but that’s another story.

Josh, your sampling was flawed.  By using packs from the same box you ensured that they all would be the same lot and production is not a random process.  If the machine is mixing incorrectly, it will continue to mix incorrectly until someone adjusts it.  You need to sample different lots over a long period of time to generate a true population estimate.  If you purchased the 48 packs at 48 different locations, you could make valid claims.

By the way, I think I saw a documentary on making M&M’s once, and they make each color on a separate production line, color them at the end in a tumbler and mix the colors together later.

I suspect, with my little industry knowledge, that the design percentage (as we can see, not necessarily the actual percentage) of blue and brown M&M’s per package was decided based on product research; specifically, how comsumers ranked each color individually and how appealing the overall color mix was.

Say what you want about all M&M’s being the same, but I bet studies show differently. Your eyes are connected to your stomach.  Remember when they came out with different colored ketchup?  That didn’t go over so hot.  Brown M&M’s are boring.  Blue (a color rarely associated with food in the natural world) is exciting and fun. 

Greetings and salutations,

I’m a QC Line Inspector for a company that makes specialty grinding wheels.  I like your approach to analyzing the tantalizing question as to whether or not the Mars company is being totally honest with us about what their product actually contains.  What you did here is EXACTLY the kind of thing we do to determine the quality of our product.

I bet you exceeded the Mars company QC standards with your testing.  At the very least if you should need another day job they should be happy to offer you one.  If they don’t I’ll be happy to recommend you to my company.

You’re good.

My minor grievance with your testing procedure involves the last line in your presentation.  You stated:

“All packages were 1.69 ounces and were from the same 48-count box. This is the standard newspaper stand/vending machine size.”

That’s interesting from a Line QC position because of the aberrations between the number of M&M’s included in each bag vs. the weight of each bag.

A bag that has 57 M&M’s shouldn’t weigh the same as a bag containing 52, yet all bags are treated as weighing 1.69 oz.  Perhaps the unit measurement of an ounce isn’t the best resolution if a gram gives a finer gradient.

Perhaps you decided to give the Mars company the benefit of the doubt (a bad idea) and took their word that each bag weighed 1.69 oz without measuring the weight of each bag yourself.  And at the resolution of an ounce maybe 1.69 is close enough for government work, but is it really close enough for what your trying to do?

Perhaps, but considering the attention to detail you spent on this project you want to get it EXACTLY right and are willing to blow another twenty bucks (((?)do you get a rate for “professional” work? I love M&M’s)) on a “case” of M&M’s to do just that.

Overall I’d have to rate the work you’ve done as superlative.  It’s certainly on a par with what we do with millions of dollars at stake, and you’ve done this just for fun.

Let me know if I can help.  I love M&M’s. 

Rikonjohn