Statistical significance in Excel

I have data from a market research survey which covers behaviour of different customer groups. To be specific, I am looking at the number of channels that a customer will visit before they buy a product.

I would like to know whether the value of the customer (as measured by the value of the product they buy) is a meaningful way of splitting the data. I have calculated the average number of channels visited for the whole sample (let's call it X) and then for customers who bought only the most expensive products (Y) and separately for customers who bought only the cheapest products (Z).

I would now like to check whether Y and Z are statistically significant. i.e. what is the probability that in my whole population I would find a customer who has bought a cheap product having visited Y or more channels beforehand.

There are a number of statistical functions in Excel that look relevant (CONFIDENCE.NORM, CONFIDENCE.T, T.TEST, etc...). Which one should I use?

• This may get a better response on the statistics SE site, which is more appropriate (SO is primarily for programming, algorithms, and the like). If you flag your question and ask for it to be moved, it will likely be accommodated. Nov 15 '11 at 23:49