Answer:
a) the holding period return (HPR) for the first 4 months = ($106 - $100) / $100 = 6%
b) the holding period return (HPR) for the next 5 months = ($107 - $106) / $106 = 0.94%
c) the holding period return (HPR) for the 9 months period = ($107 - $100) / $100 = 7%
The holding period return measures the total return on an investment over a certain period of time. It does not necessarily calculate annual returns, since the holding period can be more or less than 1 year.