Assume a department store will be using RFM analysis to identify customers for a new promotion campaign. The RFM dataset is a sample of 100,000 customers - split evenly between customers who had and had not responded to a previous campaign.

a) If the new promotion will cost $2.40 per customer and generate $25 in revenue per response, what is the break-even response rate?

b) What is the response rate for cell 050304, which has 500 respondents and 118 non-respondents?