speech signal-sampling rate conversion

This program is used to perform interpolation and decimation by a factor of 2 for a speech signal

//Caption: write a program for decimation and interpolation of given
//Speech Signal [ Multirate Signal Processing]

clear;
clc;
[x,Fs,bits]=wavread("E:\4.wav");
n = length(x)
DECIMATION_OF_X = x(1:2:length(x));
INTERPOLATION_OF_X = zeros(1,2*length(x));
INTERPOLATION_OF_X(1:2:2*length(x)) = x;
subplot(3,1,1)
plot([1:n],x)
xtitle("ORIGINAL Speech SIGNAL");
subplot(3,1,2)
plot([1:ceil((n/2))],DECIMATION_OF_X)
xtitle("DECIMATION BY A FACTOR OF 2")
subplot(3,1,3)
plot([1:2*n],INTERPOLATION_OF_X)
xtitle("INTERPOLATION BY A FACTOR OF 2")