Assume that Excel Cruiseline expects to sell three regular cruises for every executive cruise. In this mix, the weighted-average contribution margin per cruise is $65. a. Compute the total number of dinner cruises that Excel Cruiseline must sell to break even. b. Compute the number of regular cruises and executive cruises the company must sell to break even. a. Compute the total number of dinner cruises that Excel Cruiseline must sell to break even. First, enter the formula and then compute the total number of dinner cruises that Excel Cruiseline must sell to break-even. (For amounts with a zero balance, make sure to enter "0" in the appropriate cell. Abbreviations used: avg. CM = average contribution margin.) Describe what each letter stands for in the CVP graph