i need matlab code with explanation

The input data signal x(t)=sin(200t)+cos(400t)+0.4r(t) is sampled at frequency rate of 1000Hz, where r(t) is a white noise with zero mean and unit standard deviation. Generate a 100 -point input data sequence and filter this data using the filter whose transfer function is H(z)=11.1619z1+0.6959z20.1378z30.0495+0.1486z1+0.1486z2+0.0495z3 Plot the input and the output data for 0n50 Plot the spectrum of the input and output data