Answer
a. Not representative, could be inaccurate.
b. Parameter
c. Observational Study
Work Step by Step
a. They are basing the data on a survey where only 7000 people responded out of 25,000. Therefore it is not representative and could be inaccurate.
b. It is describing an entire population, therefore it is a parameter.
c. No treatment was made, therefore it is an observational study.
