To address the question, we need to understand the difference between a sample statistic and a parameter:
- Parameter: This is a value that describes a characteristic of an entire population. When we survey or measure every member of the population, we obtain a parameter.
- Sample Statistic: This is a value that describes a characteristic of a sample taken from a population. When we survey or measure a subset of the population, we obtain a sample statistic.
Given our population of 7000 people, we need to identify whether surveying a certain number of people will result in a sample statistic or a parameter.
Let's evaluate the choices:
1. Surveying 7000 people:
- If we survey all 7000 people in the population, we are not taking a sample; we are surveying the entire population. Thus, any measure we derive from this survey is a parameter.
2. Surveying 70 people:
- If we survey only 70 people out of the 7000, we are taking a subset of the population. Any measure we derive from this subset is a sample statistic since it is based on a sample, not the entire population.
Consequently, surveying the entire population (7000 people) gives us a parameter, whereas surveying a subset of 70 people gives us a sample statistic.
Therefore, given the options, the correct choice is:
C. 70
Surveying 70 members of the population can result in a sample statistic but not a parameter.
