Final answer:
The mean frequency of the wave can be calculated by taking the reciprocal of the mean time taken for the wave fronts to pass the mark. To find the mean time, add up the individual times and divide by the number of measurements. Finally, take the reciprocal of the mean time to find the mean frequency.
Step-by-step explanation:
The mean frequency of the wave can be calculated by taking the reciprocal of the mean time taken for the wave fronts to pass the mark. To find the mean time, you add up the individual times and divide by the number of measurements, which in this case is 3. So, (8.4 + 7.8 + 8.1) / 3 = 24.3 / 3 = 8.1 seconds.
Now, to find the mean frequency, you take the reciprocal of the mean time: 1 / 8.1 = 0.1235 Hz.
Therefore, the mean frequency of the wave is 0.12 Hz (to 2 significant figures).