My linear regression is:
School's average test score ~ log(%FSM)
%FSM = the percentage of pupils at the school who are eligible for free school meals (an indicator of low socio-economic status).
The coefficient for log(%FSM) is -10.
Do I interpret this as: a 1% increase in the %FSM pupils is associated with a decrease of 0.1 in average test score?
Or, because this is a log of a % is the interpretation different from the above? I think this is also a 1% increase, NOT a 1 percentage point increase. Is there a clearer way to make this distinction in my interpretation?