How to average MFCCs from different speakers saying the same word?
What you can try is the DTW (Dynamic Time Warping) distance (https://en.wikipedia.org/wiki/Dynamic_time_warping).

for each instance of the spoken word "west", you compute MFCC's per frame and then calculate the DTW distance between each of the pre-recorded instances of word. this gives the rough estimate of the valid DTW distance. now when a new instance of the word comes we again calculate DTW with one of the earlier instance and if the DTW distance lies roughly in the range calculated before, it is the same word.