Answer: Population parameter.
Step-by-step explanation:
Population parameter : It is a number that summarize a term for the whole population . For example :population proportion , population mean , etc.
Sample statistics: It is a number that summarize a term for the sample . For example : sample proportion , sample mean, etc.
By considering the given statement :
Population of interest : " all instructors at school "
Since 75% of all instructors at your school teach 2 or more classes.
It means , 75% is describing population proportion of all instructors at your school teach 2 or more classes..
i.e. The numerical value describes a population parameter.