An auto manufacturer is conducting a market study for a new model. It is afraid that the new car may cannibalize sales from its existing lineup. The sales director thinks that based on past experience, as much as 20% or more of existing buyers would move to the new model. The market research department is setting up the null hypothesis to test the effect of the new model on existing model sales. If u represents the erosion of sales of the current model, which of the following is the most appropriate null hypothesis?

Which element is "defined" in a defined benefit pension plan?