If your cumulative score is the total number of days sleeping in each location, you can use
gen totaldays = x1 + x2+ x3
as long as your days are coded as numerical, and not string, for each of the x variables.
If your cumulative score is the total number of days sleeping in each location, you can use
gen totaldays = x1 + x2+ x3
as long as your days are coded as numerical, and not string, for each of the x variables.