I have a series of figures for car sales that show me (a) the usual number of car sales for particular models and (b) the number of car sales by a particular car salesperson for each model.
Let's say the values are:
Model | Sales by all Salespeople | Sales by Salesperson x A | 100 | 20 B | 50 | 40 C | 50 | 0
I want to find out if Salesperson x is significantly more responsible for sales of a particular model.
My first thought is to determine the rate of sales per model vs the rate of sales per model for the salesperson, i.e.:
Model | % Total Sales for all Salespeople | % Total Sales for Salesperson x A | 50% | 33% B | 25% | 66% C | 25% | 0%
However, naturally every salesperson has a significant variation in the cars they sell.
- How do I determine if salesperson variation from the mean is statistically significant?
I think the Pearson correlation has some bearing, as perhaps may chi-square distribution, but I really don't have the background yet to understand why, so introductory help is appreciated.