I would like to ask for your help.

I have a product which is made with 3 materials A, B and C, where the composition mix of this product is A – 50%, B – 40%, C – 10%. These add up to be 100% in total.

Then I would like to ask a group of existing customers (e.g. 50 people) on how they estimate the composition mix of the product, that is how much A, B and C in % are used to make the product. so I will get around 50 sets of such customer rated composition mix.

I need help on which statistical test(s) should I use to:

- prove there’s difference (or no difference) between the customer estimated composition mix against the actual composition mix?

- Also, how should I prove there is individual difference on customer’s estimated composition mix?

Thank you very much.