Source filter theory of vowel production

The wavelength (λ) of the first resonant frequency (R1) will be ____ times the length of the supralaryngeal vocal tract.
An individual whose vocal tract length during production of the neutral vowel /Λ/ is 14.5 cm, produces the vowel with a fundamental period (To) of 3.5 ms.
Draw the glottal spectrum (up to 2000 Hz), the vocal tract transfer function (up to R3), and spectrum of the filtered /Λ/ (up to 2000 Hz). Be sure to label your graphs completely.