Yield is calculated as the return you get divided by the amount you invested. For example, you invest $100 for one year and get back $105 at the end of the year - your yield is 5/100 = 5%. If the investment was made for a period other than 1 year, and you want the resukts in the equaivalent annual yield, it's a little more complicated.:
Final = final value of the investment
Initial = amount initially invested
N = number of years of investment
Not sure what you are getting at with respect to hotel rooms. Please clarify.