The height of a stack of DVD cases is in a proportional relationship to the number of cases in the stack. A stack of 7 cases and its height are shown. Find the constant of proportionality. Then use the constant of proportionality to find the height of a stack of 12 cases. Golden Oldies, 2006 Golden Oldies, 2005 Golden Oldies, 2004 Golden Oldies, 2003 Golden Oldies, 2002 Golden Oldies, 2001 Golden Oldies, 2000 The height of 7 DVD cases is 91 mm The constant of proportionality is millimeters per DVD case.​