Answer :
Final answer:
The average IQ of the sample can be higher, lower, or equal to the average IQ of the entire population.
Explanation:
The correct statements regarding the average IQ of all Americans by looking at a sample of 50 people are:
I. The average IQ of the sample could be greater than the average IQ of the population.
II. The average IQ of the sample could be smaller than the average IQ of the population.
III. The average IQ of the sample must be the same as the average IQ of the population.
This means that the average IQ of the sample can be either higher, lower, or equal to the average IQ of the entire population.
