Answer: L = 0.4375m, the from observations, the length seem too long.
Explanation: Since the voice tract has been modeled to be an open close tube, then the length of pipe and wavelength is related by the formulae
L = λ/4, hence λ = 4L
But v = 350m/s, f = 200Hz and λ=4L
But v = fλ
350 = 200 * 4L
350 = 800* L
L = 350/800
L = 0.4375m
The average length of an human voice tract is between 0.169m ( 16.9cm) for male and 0.141m (14cm) for female.
Comparing this to L = 0.4375m (43.75m) means that this model for the human voice tract is very long compared to the average.
Thus the fundamental note produced won't be at 200Hz