1.  For frequency f₁ determine the total distance between the first and last Antinodes in the standing wave pattern in meters, and enter the value in cell B25.

2.  Divide the total distance obtained above by the number of loops in the pattern to determine the distance between adjacent Antinodes, d. Enter the result in cell B26.

3.  Using the fact that the distance between adjacent Antinodes is one-half the wavelength, calculate the wavelength of the sound, and enter in cell B27.

4.  Calculate the velocity of sound in air for frequency f₁, from: v₁ = f₁ λ. Enter the result in cell B28.

5.  Repeat the calculations of the total distance between first and last Antinodes, the distance between adjacent Antinodes, the wavelength, and the velocity of the sound of frequency f₂, and enter the results in cells C25:C28.

6.  Repeat the calculations of the total distance between first and last Antinodes, the distance between adjacent Antinodes, the wavelength, and the velocity of the sound of frequency f₃, and enter the results in cells D25:D28.

7.  From the three values for the velocity of sound in air, calculate the average velocity of sound in air v_avg at the temperature of the laboratory, and enter this value in cell D30.

8.  Compare your value for v_avg with the Actual Value that is calculated in cell D35, and compute the percentage difference. Enter this value in cell D36.

9.  Using the average velocity of sound in air at laboratory temperature, calculate the unknown frequency from: f_x = v_avg / λ, and enter the value in cell E32.