Variable of interest: The SAT scores of all the students entering the universities in the United States this year.
Type 1 Error: The president concludes that the mean SAT score of the entering students is not lower than previous years when it is indeed lower.
In other words:
The parameter the president is interested in is the mean SAT score of the entering students to his university this year.
The population the president is interested in is all entering students to his university this year.