A change in sales has no effect on margin and turnover.

A change in sales can have an effect on margin and turnover. For example, if sales increase but cost of goods sold remains the same, margin will increase. Similarly, an increase in sales can lead to a higher turnover. However, it is also possible for sales to change without affecting margin and turnover, such as if there is a shift in sales from one product to another with the same margin and turnover.