POSSIBLE SOLUTION(S)

1) the 120Hz tone

2) the 125 Hz tone

3) the resultant of the two harmonic oscillations

4) Use the graph produced in (3) to determine

5a) the 150 Hz tone

5b) the 156 Hz tone

5c) the resultant of the two harmonic oscillations

5d) Use the graph produced in (5c) to determine

6) The beat frequency is the numerical difference between the frequencies of the two original frequencies.