Final answer:
The observed frequency does not become infinite at the speed of sound, so the statement is False. Wave-particle duality is not applicable on the macroscopic scale, making that statement False as well.
Step-by-step explanation:
Observation Frequency and Speed of Sound
The statement that the observed frequency becomes infinite when the source is moving at the speed of sound is False. When a source moves at the speed of sound, the sound waves it produces constructively interfere, creating a shock wave known as a sonic boom. However, the frequency does not become infinite; rather, the waves are compressed into a smaller space.
Wave-particle duality is a concept that applies to subatomic particles, demonstrating that they have both wave-like and particle-like properties. This duality does not exist on the macroscopic scale, making the statement False.
Regarding the sampling distribution of the mean, it is True that the mean of a sampling distribution of means is approximately the mean of the data distribution. This is a fundamental principle of statistics known as the Central Limit Theorem.