The first and second formants when you make an "ee" vowel sound are approximately 270 Hz and 2300 Hz. The speed of sound in your vocal tract is approximately 350 m/s. If you breathe a mix of oxygen and helium (as deep-sea divers often do), the speed increases to 810 m/s .

  λ₂ = 3 m ,    λ₃ = 0.352 m

Explanation:

To find the new wavelengths we use the relationship between the speed of sound and the wavelength and frequency

                v = λ f

The frequency of vibration for being a resonant process does not change from one medium to another, therefore the frequency must change

For the first frequency

          f₀ = 270 Hz      λ = 350/270 = 1.30 m

                λ₂ = v₂ / f₀

                λ₂ = 810/270

                λ₂ = 3 m

     f₀ = 2300 Hz     λ = 350/2300 = 0.152 m

                λ₃ = 810/2300

                λ₃ = 0.352 m

We can see that the wavelength is significantly lengthened when helium is breathed

d is the correct answer

frequency or wavelenth of em radiation in a vacuum