As long as the sample size n is large enough: The average IQ of Americans in the sample will be normally distributed.
Step-by-step explanation:
The Central Limit Theorem estabilishes that, for a random variable X, with mean and standard deviation , the sample means with size n of at least 30 can be approximated to a normal distribution with mean and standard deviation
So the correct answer is:
As long as the sample size n is large enough: The average IQ of Americans in the sample will be normally distributed.